CN111457253A

CN111457253A - Gas supply system and gas supply method

Info

Publication number: CN111457253A
Application number: CN202010408984.2A
Authority: CN
Inventors: 王彦
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-05-14
Filing date: 2020-05-14
Publication date: 2020-07-28
Anticipated expiration: 2040-05-14
Also published as: CN111457253B

Abstract

The invention relates to the technical field of gas safety, in particular to a gas supply system and a gas supply method; the gas supply system includes: the pneumatic device, the gas supply pipeline and the first valve; the first valve is used for being communicated with an air source and is also communicated with pneumatic equipment through an air supply pipeline; the pneumatic equipment is used for modulating the relative pressure of the gas in the gas supply pipeline, so that the first valve can be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, and the relative pressure of the gas in the gas supply pipeline can be kept within a first pressure setting range. The gas supply method modulates the relative pressure of gas in the gas supply pipeline through the pneumatic equipment so that the first valve can be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, and the relative pressure of the gas in the gas supply pipeline can be kept within a first pressure setting range. The invention can reduce or avoid the huge potential safety hazard of fire accidents and even explosion accidents caused by accidental gas leakage to a certain extent.

Description

Gas supply system and gas supply method

Technical Field

The invention relates to the technical field of gas safety, in particular to a gas supply system and a gas supply method.

Background

At present, for gas users in industry, business, residents and the like, the gas supply of the front-end gas source of the used indoor gas equipment is basically performed in a positive pressure mode that the relative pressure (or called relative pressure) is a pressure value with a certain pressure value, such as 1-8 KPa, so that the risk of leakage of the positive pressure gas with higher relative pressure in the pipeline to the environment in the normal pressure chamber with lower relative pressure is inevitably existed in the section of gas supply pipeline from the inlet to the indoor gas equipment, and therefore, the traditional gas supply mode always has huge potential safety hazards of fire accidents and even explosion accidents caused by accidental gas leakage.

Disclosure of Invention

The invention aims to provide an air supply system and an air supply method, which aim to solve the technical problem of huge potential safety hazard of fire accidents and even explosion accidents caused by accidental gas leakage in the prior art all the time.

The present invention provides a gas supply system, comprising: the device comprises a pneumatic device, an air supply pipeline, a discharge pipeline and a first valve; the first valve is used for being communicated with an air source and is also communicated with the pneumatic equipment through the air supply pipeline; the pneumatic equipment is used for modulating the relative pressure of the gas in the gas supply pipeline, so that the first valve can be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, and the relative pressure of the gas in the gas supply pipeline can dynamically reach and be kept in a first pressure setting range.

The invention also provides a gas supply method, which comprises the following steps: communicating a first valve with an air source, and communicating the first valve with pneumatic equipment through an air supply pipeline; and then modulating the relative pressure of the gas in the gas supply pipeline through the pneumatic equipment so as to enable the first valve to be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, so that the relative pressure of the gas in the gas supply pipeline can be dynamically reached and kept within a first pressure setting range.

Compared with the prior art, the invention has the following beneficial effects:

the gas supply system and the gas supply method provided by the invention can reduce or avoid huge potential safety hazards of fire accidents and even explosion accidents caused by accidental gas leakage to a certain extent.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of an air supply system according to a first embodiment;

fig. 2 is a schematic structural diagram of an air supply system according to a second embodiment;

fig. 3 is a schematic structural diagram of an air supply system according to a third embodiment;

FIG. 4 is a schematic structural diagram of an air supply system according to a fourth embodiment;

FIG. 5 is a schematic structural diagram of a gas appliance provided in the fifth embodiment;

FIG. 6 is a schematic structural view of a supercharging apparatus according to a sixth embodiment;

FIG. 7 is a schematic structural view of a negative pressure gas outlet valve provided in the seventh embodiment;

FIG. 8 is a partial schematic view showing another modified structure of a negative pressure gas outlet valve in the seventh embodiment;

FIG. 9 is a partially enlarged schematic view of the seventh embodiment at the valve plate of the negative pressure outlet valve;

FIG. 10 is a view showing a state in which the negative pressure gas outlet valve of the seventh embodiment is opened;

FIG. 11 is a front view (in section) of the negative pressure outlet valve provided in the eighth embodiment;

FIG. 12 is a left side view (in section) of the negative pressure outlet valve provided in the eighth embodiment;

FIG. 13 is a left side view (in section) of another modification of the negative pressure outlet valve provided in the eighth embodiment;

FIG. 14 is a partially enlarged schematic view of the eighth embodiment at the valve plate of the negative pressure outlet valve;

FIG. 15a is a schematic view of the embodiment eight illustrating the manual valve in an open state during a normal operation when the gas in the liquefied gas tank has a saturated vapor pressure;

FIG. 15b is a schematic diagram of an embodiment eight illustrating a manual valve in a closed state during an abnormal operation state where the gas in the liquefied gas tank has an unsaturated vapor pressure;

FIG. 15c is a schematic view showing the state of the manual valve being closed when the manual valve is manually closed in the eighth embodiment;

FIG. 16a is a front view of an open valve stem of the eighth embodiment;

FIG. 16b is a plan view of an open valve stem of the eighth embodiment;

fig. 17 is a state diagram of the negative pressure gas outlet valve in the maximum opening degree according to the eighth embodiment.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention relates to a safe gas supply system with a user side at negative pressure, normal pressure or micro-positive pressure. The pressure involved in the invention refers to relative pressure. At present, the front-end gas supply of indoor gas equipment of industrial, commercial, residential and other gas users is basically supplied in a positive pressure mode with a certain pressure value, such as a pressure value of 1-8 KPa, relative pressure, so that the risk of leakage of positive pressure gas with higher relative pressure in a pipeline to an indoor environment with lower relative pressure and normal pressure is inevitably existed in a section of gas supply pipeline from the indoor to the indoor gas equipment, therefore, the traditional gas supply mode always has huge potential safety hazards of fire accidents and even explosion accidents caused by accidental gas leakage, and a lot of serious accidents happen in the use process of the gas users for a long time. The specific principle scheme of the invention is as follows: the gas flowing through the pipeline of the traditional user indoor gas supply system is in a positive pressure state with a certain pressure value relative to the pressure for a long time, and due to the positive pressure difference with the normal-pressure indoor environment space, the risk of leakage of the gas in the system to the normal-pressure indoor environment space caused by the accidental situations of poor sealing, accidental damage, system aging, misoperation, artificial damage and the like exists at any time. When the relative pressure value of the gas in the system is reduced, the gas is closer to a micro positive pressure state of normal pressure under the condition of keeping the positive pressure state, and the flow speed of the gas during leakage can be reduced when the gas is leaked in an unexpected situation, so that the gas leakage rate is reduced in unit time, and the risk of the gas leaking indoors is reduced; when the relative pressure value in the system is reduced to enable the system to reach a normal pressure state, the leakage flow rate is basically not leaked under the condition of accidental leakage, the gas leakage is mainly carried out in a gas molecule diffusion movement mode, the gas leakage amount in unit time is greatly reduced, and further the risk of the gas leaking into a room is greatly reduced; when the relative pressure value in the system is reduced to enable the system to reach a negative pressure state, no fuel gas leaks into the room when an accidental leakage condition is met, and the risk of fuel gas leakage into the room is thoroughly eliminated. It should be noted that, in the present invention, as for the pressure of the gas, the pressure of the gas generally refers to the relative pressure, unless otherwise specified.

The invention is based on any one of the three pressure states selected according to different conditions and decisions, and realizes the reduction or elimination of risks brought by gas leakage to the indoor of a gas user according to the corresponding principle. The traditional user indoor gas supply system is a positive pressure gas supply system, and the main aim of the system is to (firstly) ensure the supplementary conveying capacity of the consumed gas when the indoor traditional gas equipment works by utilizing the positive pressure difference between the positive pressure gas in a system pipeline and the normal pressure indoor environment space; the normal work of the traditional gas equipment needs the gas to have a certain positive pressure value in the design of the working principle, and if the gas flow speed is required to inject and absorb mixed air under a certain pressure, and the like. And thirdly, the positive pressure difference between the positive pressure fuel gas in the system pipeline and the normal pressure indoor environment space is utilized to prevent the indoor air from flowing backwards to enter the air supply system, so that the risk of backfire explosion is brought to the system. Therefore, simply and directly reducing the gas pressure of the conventional positive pressure gas supply system to a micro-positive pressure, a normal pressure or a negative pressure state loses the support for the purpose, and thus, the method is not practical and feasible.

Example one

An embodiment of the present invention provides an air supply system, which includes: the pneumatic device, the gas supply pipeline and the first valve; the first valve is used for being communicated with an air source and is also communicated with pneumatic equipment through an air supply pipeline; the pneumatic equipment is used for modulating the relative pressure of the gas in the gas supply pipeline so as to enable the first valve to be opened or closed, and control the on-off between the gas source and the gas supply pipeline, so that the relative pressure of the gas in the gas supply pipeline can dynamically reach and be kept within a first pressure setting range.

The gas supply system also comprises a first pressure sensor which is positioned at the upstream of the first valve to monitor whether the relative pressure of the gas source gas is positive pressure or not, and has a certain positive pressure value which is used as a necessary condition for opening the first valve and the second valve.

The first valve is a normally closed electromagnetic valve or an electrically operated valve; when the relative pressure of the gas in the gas supply pipeline is reduced to be not higher than the lower limit value of the first pressure setting range, the first valve is opened; after the first valve is opened, when the gas delivered by the gas source enters the gas supply pipeline through the first valve, and the relative pressure of the gas in the gas supply pipeline rises to be not lower than the upper limit value of the first pressure setting range, the first valve is closed.

The gas supply system also comprises a second valve; the second valve is arranged on the air supply pipeline and is positioned at the downstream of the first valve; when the relative pressure of the gas in the gas supply pipeline rises to be not lower than the upper limit value of the second pressure setting range, the second valve is closed; after the second valve is closed, when the relative pressure of the gas in the gas supply pipeline is reduced to be not higher than the lower limit value of a second pressure setting range, the second valve is opened; the lower limit value of the second pressure setting range is equal to the upper limit value of the first pressure setting range.

The gas supply system also comprises a first gas storage tank; a first air reservoir is disposed on the air supply conduit, and the first air reservoir is located downstream of the second valve.

The air supply system also comprises a third valve, the air supply pipeline comprises an indoor section and an outdoor section, and the indoor section is communicated with the outdoor section through the third valve; the third valve is arranged on the gas supply pipeline and is positioned at the downstream of the first gas storage tank; the first valve, the second valve, the first gas storage tank and the third valve are arranged on the outdoor section in sequence; the pneumatic equipment is communicated with the indoor section; when the relative pressure of the gas in the indoor section rises to be not lower than the upper limit value of the second pressure setting range, closing the third valve; and after the third valve is closed, when the relative pressure of the gas in the indoor section is reduced to be not higher than the lower limit value of the second pressure setting range, the third valve is opened. The outdoor space may be an open air, a semi-open air, or a dedicated facility room with safety measures and good natural ventilation, and does not necessarily mean a real open air.

The gas supply system also comprises a second pressure sensor, and the first gas storage tank is provided with at least one second pressure sensor for monitoring the relative pressure of the gas in the first gas storage tank.

The gas supply system further comprises a first oxygen content sensor, and at least one first oxygen content sensor is arranged on the first gas storage tank and used for monitoring the oxygen content of gas in the first gas storage tank.

The gas supply system also comprises a fourth valve and a discharge pipeline, wherein the fourth valve is arranged on the discharge pipeline, and the first gas storage tank is communicated with the discharge pipeline through the fourth valve; the discharge pipeline is also provided with first air extraction equipment, and the tail end of the discharge pipeline is also provided with a dispersion port; the first air extraction equipment is positioned at the downstream of the fourth valve and the fifth valve;

when the first oxygen content sensor monitors that the oxygen content of the gas in the first gas storage tank is not lower than the upper limit value of the set range of the first oxygen content, the first air extraction equipment is started, the fourth valve is opened in a delayed mode, and the gas in the first gas storage tank is discharged outdoors through the release port; and in the process of discharging the gas in the first gas storage tank to the outdoor, when the first oxygen content sensor monitors that the oxygen content of the gas in the first gas storage tank is not higher than the lower limit value of the set range of the first oxygen content, the fourth valve is closed, and the first air extraction equipment is closed in a delayed mode.

The gas supply system also comprises a third pressure sensor, the third pressure sensor is arranged on the discharge pipeline, and the third pressure sensor is positioned between the fourth valve and the first air extraction equipment;

the third pressure sensor is used for monitoring that the pressure value generated by the suction end of the first suction device is not higher than the lower limit value of the first pressure setting range, and the third pressure sensor is used as a necessary condition for opening the fourth valve or/and the fifth valve.

The gas supply system also comprises a second oxygen content sensor, and at least one second oxygen content sensor is arranged on the indoor section and used for monitoring the oxygen content of the gas in the indoor section.

The gas supply system also comprises a fourth pressure sensor, and at least one fourth pressure sensor is arranged on the indoor section and used for monitoring the relative pressure of gas in the indoor section.

The air supply system also comprises a fifth valve which is arranged on the indoor section; one end of the indoor section is communicated with the third valve, and the other end of the indoor section is communicated with the discharge pipeline;

when the second oxygen content sensor monitors that the oxygen content of the gas in the indoor section is not lower than the upper limit value of the set range of the second oxygen content, the first air extraction equipment is started, the fifth valve is opened in a delayed mode, and the gas in the indoor section is discharged to the outside through the bleeding opening to remove air; when the second oxygen content sensor monitors that the oxygen content of the gas in the indoor section is not higher than the lower limit value of the set range of the second oxygen content, the fifth valve is closed, and the first air extraction equipment is closed in a delayed manner; the second oxygen content setting range may be equal to the first oxygen content setting range.

When the fourth pressure sensor monitors that the relative pressure of the gas in the indoor section is not lower than the upper limit value of the third pressure setting range, the first air pumping device is started, the fifth valve is opened in a delayed mode, the gas in the indoor section is discharged to the outside through the diffusing port to reduce the pressure, the gas supply system is started to alarm, and the first valve, the second valve and the third valve are all in an alarm closing state in the alarm state; in the process of discharging the gas in the indoor section to the outdoor, when the fourth pressure sensor monitors that the relative pressure of the gas in the indoor section is not higher than the lower limit value of the third pressure setting range, the fifth valve is closed, the first air extraction equipment is closed in a delayed mode, and meanwhile, the gas supply system continues to keep an alarm prompting state until the gas is recovered after manual troubleshooting; the lower limit value of the third pressure setting range may be equal to the lower limit value of the second pressure setting range.

As shown in fig. 1, the air supply system is connected from the outlet end of the manual valve of the traditional foreline positive pressure system with the manual valve, and the foreline positive pressure system is still in the positive pressure working state of the traditional system, so that the risk of backflow of ambient air into the foreline system is avoided, and meanwhile, the positive pressure gas conveying capacity of the foreline system is still possessed. The negative pressure power source of the gas supply system is mainly provided by the second air extraction device in the pressurization assembly 35 in the gas equipment 28 matched with the gas supply system or/and the second air extraction device in the pressurization assembly 35 in the pressurization device 29 arranged for matched application of the traditional gas equipment, and the first air extraction device 22 is provided as an auxiliary device (for example, after the system is installed or overhauled, the gas pressure of the gas is adjusted to be within a first pressure setting range for the system for the first time).

The gas supply system is specifically explained by taking the relative pressure of gas in the system as negative pressure as an example; in this embodiment, the gas supply system may also be referred to as a negative pressure gas supply system, since the relative pressure of the gas in the gas supply system is negative. The embodiment specifically describes the negative pressure air supply system as an example, and the negative pressure air supply system is preferred because it has the advantages of ensuring that the gas supply pipeline at the indoor section of the user cannot generate accidental gas leakage, the pressure of the gas in the negative pressure air supply system during normal operation is set within the range from the lower limit value of-200 Pa to the upper limit value of-100 Pa, and belongs to micro negative pressure, the purpose is to make the relative pressure of the gas in the air supply system not form too large reverse pressure difference with the air under the external environment normal pressure as far as possible, reduce the risk of air flowing back into the negative pressure air supply system under the accidental condition, the difference between the upper limit value and the lower limit value is selected as 100Pa, so that the fluctuation range of the relative pressure of the gas in the air supply system is ensured not to be too large as far as possible during the operation of the air supply system, so that the relative pressure of the gas in the air supply system can be relatively stable, the resolution precision requirement on the pressure monitoring device is not too high, so that the cost is reduced, meanwhile, the relative pressure of gas in the gas supply system can be really and effectively controlled, the misoperation risk is reduced, certainly, the setting of the range high and low values and the range size value is not limited to the above, and the setting can be selected according to different conditions and conditions, such as the safety and reliability of the pipeline structure of the gas supply system, the resolution or sensitivity of the pressure sensor, the gas storage volumes of the gas supply system pipeline and the gas storage tank, the total gas heat load and the use peak value of the gas carried by the gas supply system, and the like.

This air supply system's initial incoming end is equipped with hose connection 1, and its effect is the negative mechanical nature interference or the damage that this air supply system probably brought to the preceding stage system of furthest's avoidance, also is convenient for simultaneously construct the installation.

Be equipped with first manual valve 2 behind hose connection 1 as with preceding stage system, traditional malleation system's manual isolating valve that cuts off promptly can close this valve manually according to the demand when the circumstances such as air supply system installation, earlier stage inert gas sweep replacement air, maintenance.

The process port 3 is arranged behind the first manual valve 2, the process port 3 is in a sealing and blocking state during the normal working period of the gas supply system, when the inert gas replacement purging is required to be carried out on the gas supply system, the process port 3 is opened to serve as an inert gas inlet, the process port 3 can also be fixedly provided with the manual valve, and a sealing plug is arranged at the other end of the manual valve on the process port 3.

And a first pressure sensor 4 is arranged behind the process port 3 and is responsible for monitoring whether the gas pressure of the preceding stage gas source system is in a normal positive pressure working state in real time, and transmitting a signal to a first control unit 24 arranged in the gas supply system in real time so as to monitor that the positive pressure with a certain sufficient value is taken as a necessary condition for opening the first valve and the second valve. When the condition is not met, the air supply system can be started to alarm, so that the situation that the pressure of the backing system is influenced by the negative pressure system under the extreme accident condition, the backing system is in a negative pressure state, the risk that air flows backward and enters the backing system is avoided, and the extreme accident condition is the unexpected air break of the backing system. The foreline system is a traditional positive pressure system; the fore system is used as a gas source to provide fuel gas.

A first valve 5 is arranged behind the first pressure sensor 4, and the first valve 5 may be a solenoid valve, and specifically may be a normally closed solenoid valve. The first valve 5 is used for dynamically adjusting and controlling the gas pressure in the gas supply system, and the specific working process is that the gas pressure of the gas supply system is controlled and adjusted to be maintained in a range between a lower limit value and an upper limit value according to the lower limit value and the upper limit value of the negative pressure gas supply system in a first pressure setting range by timely opening or closing the first valve 5, wherein the lower limit value of the first pressure setting range is-200 Pa, and the upper limit value of the first pressure setting range is-100 Pa. It should be noted that, since the negative pressure air supply system is used in this embodiment, both the lower limit value and the upper limit value of the first pressure setting range are negative values.

The negative pressure gas supply system is provided with a second pressure sensor 15 and a fourth pressure sensor 32 which are responsible for monitoring the pressure of gas in the gas supply system in real time and transmitting signals to a first control unit 24 arranged in the gas supply system in real time, the first control unit 24 is used for controlling the opening or closing of the first valve 5, and the first valve 5 is closed when the pressure value of a preset switch action point of the first valve 5 is equal to or higher than-100 Pa; and is turned on at or below-200 Pa. As the gas equipment at the user end draws and consumes the gas in the gas supply system, the pressure of the gas in the gas supply system decreases, and when the second pressure sensor 15 or/and the fourth pressure sensor 32 monitor that the system pressure decreases to be equal to or lower than-200 Pa, the first valve 5 is opened (it should be noted that the closing is preferentially performed when the action conditions of the second pressure sensor 15 and the fourth pressure sensor 32 conflict with each other); after the first valve 5 is opened, because the pressure value of the preceding stage system is relatively high and a sufficient amount of positive pressure fuel gas enters the negative pressure system under the action of the positive pressure difference, the negative pressure system is fully supplemented by the positive pressure fuel gas, the pressure is increased, the first valve 5 is always kept in an open state before reaching-100 Pa, when the second pressure sensor 15 or/and the fourth pressure sensor 32 monitor that the pressure of the gas in the gas supply system is increased to be equal to or higher than-100 Pa, the first valve 5 is closed (it needs to be noted that the closing is preferentially executed under the condition of conflict between the action conditions of the second pressure sensor 15 and the fourth pressure sensor 32), so that the pressure in the system is dynamically kept between the micro negative pressure range values of-200 Pa to-100 Pa. It should be noted that the first valve 5 can also be an electric valve, and the opening degree of the electric valve is controlled by the first control unit 24 to achieve the same purpose.

A second valve 6 is arranged behind the first valve 5, and the second valve 6 can be an electromagnetic valve, in particular a normally closed electromagnetic valve; the second valve 6 belongs to a safety protection valve in the system and plays a plurality of safety protection roles, (one) under the control of the first control unit 24, when the system monitors that the outdoor section is monitored by the second pressure sensor 15, or/and the fourth pressure sensor 32 monitors that the relative pressure of the gas in the indoor section is unexpectedly increased to be equal to or higher than the upper limit value of the second pressure setting range, namely-50 Pa, the second valve 6 is closed, so as to cut off the supplementary supply of the gas to the gas supply pipeline and avoid the purpose of leakage risk caused by further increase of the relative pressure of the gas in the gas supply pipeline (it should be noted that the closing is preferentially performed under the condition of conflict between the action conditions of the second pressure sensor 15 and the fourth pressure sensor 32); when the system monitors that the outdoor section is at or below the lower limit of the second pressure setting range, i.e., -100Pa, by the second pressure sensor 15, or/and the fourth pressure sensor 32, the relative pressure of the gas in the indoor section is reduced, the second valve 6 is opened (note that the second pressure sensor 15 and the fourth pressure sensor 32 are preferably closed in case of conflict between the operating conditions). And (II) under the control of the first control unit 24, when the system monitors that the oxygen content of the gas in the outdoor section is equal to or higher than the upper limit value of the set range of the first oxygen content through the first oxygen content sensor 16, the system starts an emptying mechanism, and when the gas cannot be emptied within a certain emptying time limit, the system is controlled by the first control unit 24, the second valve 6 is closed, and meanwhile, the system stops running and gives an alarm until the manual emptying is recovered. And (III) when the system is powered off accidentally, the second valve 6 is closed in time, and the positive pressure gas supply is cut off. And (IV) when other accidents such as fire, earthquake and the like occur, the second valve 6 is automatically or manually controlled to be closed in an emergency manner, so that the gas supply is effectively cut off in time. And (V) the temporary cut-off protection is used for maintenance.

The second valve 6 is arranged behind the first valve 5, and due to the regulation of the first valve 5 on the system pressure, under the normal condition, the pressure of gas in the system can not reach the upper limit value of the set range of the second pressure, namely-50 Pa, and the second valve 6 is kept in an open state after being opened if the pressure is not in other conditions, so that the work fatigue damage caused by frequent starting is avoided at ordinary times, and the valve closing function can be effectively exerted when an accident happens.

A first one-way valve 7 is arranged behind the second valve 6, and the first one-way valve 7 can be a spring one-way valve; the function of the device is to prevent various unexpected high pressures such as backfire and deflagration, explosion and the like in the system from impacting the backing system.

A first pressure relief device 8 is arranged behind the first one-way valve 7 and is used for timely relieving the pressure protection system when the system is subjected to unexpected high pressure such as internal tempering, explosion and the like.

The first pressure relief device 8 can be an open type (such as a pressure-bearing rupture diaphragm type) which is opened once when meeting overpressure, and is provided with an action detection electric device, when the pressure-bearing rupture diaphragm type device acts when meeting overpressure, a signal is transmitted to the first control unit 24, the air supply system stops normal operation under the control of a preset program of the first control unit 24, the first valve 5, the second valve 6 and the third valve 13 are forced to be closed and kept, meanwhile, the first alarm device 25 electrically connected with the first control unit 24 is started to alarm, and the state is still kept even if power is cut off and power is supplied again until the state is recovered after manual repair.

Be equipped with first gas holder 9 behind first pressure relief device 8, its effect is: the proper volume of the gas storage tank is used for storing a certain amount of gas, the fluctuation frequency of the pressure intensity when the system works is reduced, the frequent starting times of the first valve 5 are reduced, the impact of the high-frequency fluctuation of the pressure intensity of the system on the second pressure intensity sensor 15 is reduced, and the authenticity and the accuracy of the pressure intensity monitoring of the second pressure intensity sensor 15 on the system are facilitated. And (II) the device also has the function of a branch cylinder, one or more outlets can be arranged, and the outlets can be connected with a main pipe, a branch pipe or the main pipe and the branch pipe.

It should be noted that the first air storage tank 9 may be replaced by a system pipe having a certain diameter and length and a sufficiently large volume. On the basis of arranging the second pressure sensor 15, the first oxygen content sensor 16 and the discharge port 18 at reasonable positions, a certain volume of system pipeline is selected to replace the first air storage tank 9, so that the safety is better, and in extreme cases, only tempering is usually performed until self-extinguishing, but explosion is not performed. And this embodiment is with choosing first gas holder as the option, according to gas equipment quantity and load condition, strict and reasonable selection sets up a first gas holder or sets up a plurality of first gas holders and connects in parallel, so can control the volume of single first gas holder, and then the risk of control container explosion, because can form the gas of explosion and the reason of air ratio limit, if promptly: the explosion limit of natural gas is 5% -15%, the explosion limit of liquefied petroleum gas is 1.7% -9.7%, the gas quantity in the first gas storage tank with reasonable volume capable of forming explosion concentration is much less than the air quantity, the explosion energy of the small gas quantity is very small and controllable even if the small gas quantity explodes under extreme conditions, and the explosion risk formed by the negative pressure system is caused by that air flows backwards into the gas container, namely, the container is filled with gas firstly, air flows backwards gradually under extreme accident conditions, the air quantity in the process of forming explosion concentration is far higher than that of gas, compared with the process that the container is filled with air firstly, gas leaks gradually and then forms explosion concentration, the process time is much longer, and the system can monitor in time and eliminate hidden danger greatly.

The first air storage tank 9 is provided with a first air inlet 10 and a first air outlet 11, and the arrangement of the first air outlet 11 on the first air storage tank 9 can be one or more.

The second check valve 12 is arranged behind the first air outlet 11, the second check valve 12 can be a spring type check valve, and the function of the second check valve is mainly to prevent the room air of the normal pressure in the indoor section of the system from flowing backwards to enter the first air storage tank 9 and the outdoor section in an unexpected situation.

A third valve 13 is arranged behind the second one-way valve 12, and the third valve 13 can be an electromagnetic valve, specifically a normally closed electromagnetic valve; the electric dividing isolation valve used as the dividing boundary of the system entering the indoor section has the functions of: under the control of the first control unit 24, when the system monitors that the relative pressure of the gas in the indoor section is unexpectedly increased to be equal to or higher than the upper limit value of the second pressure setting range, namely-50 Pa, through the fourth pressure sensor 32, the third valve 13 is closed, so that the supplementary supply of the gas to the indoor section is cut off, and the purpose of avoiding the leakage risk caused by the further increase of the relative pressure of the gas in the indoor section is achieved; when the system monitors via the fourth pressure sensor 32 that the relative pressure of the gas in the chamber section has dropped to a value equal to or below the lower limit of the second set range of pressures, i.e. -100Pa, the third valve 13 is opened. When the third valve 13 is in a closed state before being opened, when the system monitors that the relative pressure of the gas in the indoor section is still continuously increased to be equal to or higher than the upper limit value of the third pressure setting range, namely-10 Pa, through the fourth pressure sensor 32, the system further starts an emptying mechanism at the moment, actively reduces the pressure of the gas in the indoor section, avoids leakage risk caused by continuous increase of the relative pressure of the gas in the indoor section, and simultaneously controls the first alarm device 25 to start alarm, and closes the third valve 13 and keeps the same until manual investigation and repair are carried out; secondly, under the control of the first control unit 24, when the system monitors that the oxygen content of the gas in the indoor section is equal to or higher than the upper limit value of the set range of the second oxygen content through the second oxygen content sensor 31, the system starts an emptying mechanism, and controls the first alarm device 25 to start an alarm and close and keep the third valve 13 when the gas cannot be emptied within a certain emptying time limit until the gas is manually checked and repaired; and (III) the device is used for cutting off and isolating the outdoor section and the indoor section, and is convenient for the work of system construction, debugging, maintenance, repair and the like.

And a second manual valve 14 is arranged behind the third valve 13, is used as a boundary manual isolation valve of the indoor section where the system enters, is mainly used for manually cutting off and isolating the outdoor section from the indoor section, and is convenient for the construction, debugging, maintenance, repair and the like of the system.

The first gas storage tank 9 is provided with a second pressure sensor 15, which is used for monitoring the pressure of the gas in the system and transmitting the pressure to the first control unit 24 in real time. The second pressure sensor 15 may be disposed on the first air tank 9 in one or more ways, and may be disposed repeatedly on the system pipe other than the first air tank 9.

The first gas storage tank 9 is provided with a first oxygen content sensor 16 which is used for monitoring the oxygen content of the gas in the system and transmitting the oxygen content to a first control unit 24 in real time so as to judge whether air exists in the system. The arrangement of the first oxygen content sensor 16 on the first gas storage tank 9 can be one or more, and can also be repeatedly arranged on the system pipeline outside the first gas storage tank 9, so as to be beneficial to effectively monitoring the oxygen content of the gas in the system in time.

The first air storage tank 9 is provided with a second pressure relief device 17 which is used for timely removing the pressure protection container and system when accidental high pressure such as internal tempering, explosion and the like occurs in the container or system of the first air storage tank 9.

The second pressure relief device 17 can be an open type (such as a pressure-bearing rupture diaphragm type) which is opened once when meeting overpressure, and is provided with an action detection electric device, when the second pressure relief device acts when meeting overpressure, a signal is transmitted to the first control unit 24, under the control of a preset program of the first control unit 24, the negative pressure air supply system stops normal operation, the other first valve 5, the second valve 6 and the third valve 13 are forced to be closed and kept, meanwhile, the first alarm device 25 is started to alarm, and the state is still kept even after power failure and re-feeding point until the second pressure relief device is recovered after manual repair.

The first air storage tank 9 is provided with a discharge port 18, and the functions of the first air storage tank are as follows: and (I) when air is mixed in the system and the first air pumping device is started, the air is used as a discharge port for emptying. And (II) the system is used as a gas discharge port of the system when inert gas replacement purging, pre-pumping negative pressure and gas replacement are carried out on the system at the beginning of use. The upper and lower positions of the first air storage tank 9 are arranged to follow the first oxygen content sensor 16 to facilitate the discharge of air.

The discharge outlet 18 is followed by a discharge conduit which is first provided with a third one-way valve 19, which third one-way valve 19 may be a spring-type one-way valve, and which is mainly intended to prevent atmospheric outdoor air from flowing backwards through the discharge conduit into the first air reservoir 9 in the event of an accident.

A fourth valve 20 is arranged behind the third check valve 19, the fourth valve 20 may be an electromagnetic valve, and specifically may be a normally closed electromagnetic valve, and functions as a control valve for discharging the gas in the outdoor section including the first gas storage tank 9 to the outside through a discharge pipeline, and the operation of the control valve is controlled by the first control unit 24, and the main functions and working processes of the control valve are as follows: when the first control unit 24 monitors that the oxygen content of the gas in the first gas storage tank 9 is equal to or higher than the upper limit value of the first oxygen content setting range through the first oxygen content sensor 16, it indicates that a certain amount of air exists in the system, at this time, the first air extraction device 22 is automatically controlled to be started, and then the fourth valve 20 is opened in a delayed manner to discharge the gas in the first gas storage tank 9 or/and the outdoor section to the outside through the discharge pipeline through the discharge port 23, so that the air is discharged together with the gas, and when the oxygen content monitored by the first oxygen content sensor 16 is equal to or lower than the lower limit value of the first oxygen content setting range in the discharge process, the fourth valve 20 is automatically controlled to be closed, and meanwhile, the first air extraction device 22 is also stopped in a delayed manner; and (II) when the system is pre-purged by replacing air with inert gas before the system is used for the first time after installation or maintenance, replacing the inert gas with fuel gas and pre-adjusting the system pressure to a first pressure setting range, manually controlling the opening/closing of the fourth valve 20 and the starting/stopping of the first air extraction equipment 22 through the first control unit 24.

The third pressure sensor 21 is arranged behind the fourth valve 20, and is used for monitoring whether the working state of the first pumping device 22 is normal or not in a manner of monitoring whether the pressure value generated by the suction end of the first pumping device 22 is low enough or not when the first pumping device 22 is controlled to be started by the first control unit 24, and monitoring that the working state is lower than the lower limit value of the first pressure setting range, namely lower than-200 Pa, by the third pressure sensor 21 as a necessary condition for opening the fourth valve 20 or/and the fifth valve 34, so as to ensure that no reverse flow air flow exists when the fourth valve 20 or/and the fifth valve 34 are opened, and prevent external ambient air from accidentally flowing backwards into the system.

The first air extractor 22 is arranged behind the third pressure sensor 21, and has the functions that before the fourth valve 20 or/and the fifth valve 34 are opened for executing various functions, the first air extractor 22 is started before being started, after the fourth valve 20 or/and the fifth valve 34 are closed each time, the first air extractor is stopped later, the purposes of extracting the gas in the system and discharging the gas to the outside through the discharge port 23 are achieved, and no reverse airflow flowing between the system is ensured through an advance/retard matching sequence between the opening/closing actions of the fourth valve 20 or/and the fifth valve 34, and the air is prevented from entering the system. It should be noted that a bypass line with a bypass valve may be provided between the suction end and the discharge end of the first pumping device 22, and the bypass valve may be opened at a necessary moment, such as a positive pressure purge of the inert gas in the system, to improve the discharge efficiency.

The first air extractor 22 is provided with a diffusing port 23 at the rear, which is arranged in a safe outdoor space, and the system gas used in various situations is discharged and diffused to the outside through the first air extractor 22.

The gas supply system also comprises a first control unit 24 which serves to provide integrated control of the operation of the system. It should be noted that the first control unit 24 can interface with external equipment to facilitate other related integrated control and value-added functions of the system.

The first control unit 24 is connected with a first alarm device 25 which is controlled by the first control unit 24, plays a role of alarm prompt when various accidents needing to be alarmed occur, and can remotely transmit alarm signals.

In this example, the part of the indoor section behind the second manual valve 14 is a gas main pipe, the gas main pipe is provided with a plurality of gas branch pipes, the gas branch pipes are provided with fourth check valves 26, and the fourth check valves 26 are spring type check valves, which are used for preventing indoor air from flowing backwards into the system under various accidental conditions at the user gas equipment end.

The gas branch pipe is also provided with a third manual valve 27, the third manual valve 27 is positioned at the downstream of the fourth one-way valve 26, and the third manual valve is used as a manual isolation valve between the system and the gas equipment and is mainly used for cutting off and isolating the system when the gas equipment end is idle, installed and maintained, is not used for a long time and the like.

Downstream of the third manual valve 27, pneumatic devices are respectively installed, which may be gas devices 28 with a boosting function, or pneumatic devices may be boosting devices 29; the concrete structure of the gas equipment 28 is shown in the fifth embodiment, and the concrete structure of the supercharging device 29 is shown in the sixth embodiment.

And a gas device 28 with a pressurization function is arranged behind the third manual valve 27 on one branch pipe, the gas device 28 is a gas application device matched with the system, not only plays the application function of a user, but also serves as one of negative pressure power sources of the system, and the second air extraction device in the pressurization assembly 35 provides a negative pressure power source for the formation of negative pressure of the system while continuously extracting the gas in the system for the gas supply device to work and apply. The gas appliance 28 may be a gas cooker, a gas water heater, a gas boiler, or the like.

And/or a branch pipe is provided with a pressure boosting device 29 after the third manual valve 27, and the pressure boosting device 29 is a matching device applied to the system by the traditional gas equipment. The second air extraction device in the supercharging component 35 provides a negative pressure power source for the formation of the negative pressure of the system while continuously extracting the gas in the system for the gas supply device to work and apply.

The traditional gas equipment 30 is arranged behind the supercharging device 29, and the traditional gas equipment 30 can be equipment such as a gas cooker, a gas water heater, a gas boiler and the like; this is a customer-applied gas facility used in the system, and since the pressurizing device 29 is provided between the gas inlet end and the branch pipe of the negative pressure gas supply system, the conventional gas facility used in the conventional positive pressure gas supply system can still be used in the negative pressure gas supply system depending on its function.

The indoor gas main pipe behind the second manual valve 14 is provided with at least one second oxygen content sensor 31, the oxygen content of the gas in the indoor gas main pipe is monitored and transmitted to the first control unit 24 in real time, whether air exists in the system is further judged, the specific setting position of the second oxygen content sensor on the gas main pipe is determined according to different gas type densities, different air densities, different pipeline distance lengths, different pipeline layouts and other comprehensive factors, and the second oxygen content sensor is arranged at a position which is most favorable for fast and effectively playing a monitoring function.

After the second oxygen sensor 31, at the end section of the gas main, a fourth pressure sensor 32 is provided, which is used to monitor the relative pressure of the gas in the gas main and transmit it to the first control unit 24 in real time.

A fifth check valve 33 is arranged behind the fourth pressure sensor 32, the fifth check valve 33 is a spring-type check valve, and the function of the fifth check valve is to prevent the outdoor air with normal pressure from flowing backward into the indoor section through the discharge pipeline in an unexpected situation.

A fifth valve 34 is arranged behind the fifth check valve 33, and the fifth valve 34 can be an electromagnetic valve, specifically a normally closed electromagnetic valve; the function is as a control valve for discharging gas in the indoor section of the system to the outside, the action is controlled by the first control unit 24, and the main functions and the working process are as follows: when the first control unit 24 monitors that the relative pressure of the gas in the indoor section rises to be equal to or higher than the upper limit value of the third pressure setting range, namely-10 Pa, through the fourth pressure sensor 32, the first air suction device 22 is controlled to be started, then the fifth valve 34 is opened in a delayed mode, the gas in the indoor section is discharged to the outside through the vent so as to reduce the relative pressure of the gas in the indoor section, and meanwhile, the first alarm device 25 is controlled to start an alarm and close and keep the first valve, the second valve and the third valve; in the process of discharging the gas in the indoor section to the outdoor, when the fourth pressure sensor monitors that the relative pressure of the gas in the indoor section is reduced to be equal to or lower than the lower limit value of the set range of the third pressure, namely-100 Pa, the fifth valve is controlled to be closed, the first air extraction equipment is closed in a delayed mode, and meanwhile, the gas supply system continues to keep the alarm and the closed states of the first valve, the second valve and the third valve until the gas is recovered after manual troubleshooting; (II) when the first control unit 24 monitors that the oxygen content of the gas in the indoor section of the system is equal to or higher than the upper limit value of the set range of the second oxygen content through the second oxygen content sensor 31, the existence of a certain amount of air in the indoor section of the system is indicated, the first air extraction equipment 22 is automatically controlled to be started at the moment, and then the fifth valve 34 is started after delay to discharge the gas in the indoor section to the outside through the diffusion port 23, so that the air is discharged together; during the discharging process, when the oxygen content detected by the second oxygen content sensor 31 is equal to or lower than the lower limit value of the set range of the second oxygen content, the fifth valve 34 is automatically controlled to be closed, and the first air extraction device 22 is also stopped with delay. In the discharging process, if the first control unit 24 cannot monitor that the oxygen content is equal to or lower than the lower limit value of the set range of the second oxygen content through the second oxygen content sensor 31 within the preset time range, the first alarm device 25 is controlled to start the alarm and the third valve 13 is controlled to be closed and kept until the manual investigation is recovered; and (III) after the system is installed or maintained, when the system is pre-purged by replacing air with inert gas before the system is used for the first time, replacing the inert gas with fuel gas and pre-adjusting the pressure of the system to a first pressure setting range, manually controlling the opening/closing of the fifth valve 34 and the starting/stopping of the first air extraction equipment 22 through the first control unit 24.

In this embodiment, the gas supply system has the following advantages: and (I) indoor fuel gas leakage is avoided, life and property loss is avoided, and safety is guaranteed. And (II) because each pneumatic device is provided with a gas conveying power source, namely a vacuum/pressure pump, the pressure difference conveying capacity formed at the two ends of the inlet/outlet of the powered vacuum/pressure pump is far higher than the conveying capacity formed by the gas positive pressure of the traditional gas supply system, the power sources are dynamic, timely and self-adaptive, and the improvement of the gas conveying capacity is also self-adaptive. On original pipeline design and original pipeline installation basis in kind, the gas is carried supply capacity and is improved greatly, and the phenomenon is pressed to insufficient gas, insufficient pressure that takes place when can to a great extent avoid or even stop because many loads use simultaneously has ensured the burning operating mode of load gas equipment, does benefit to energy-conservation and environmental protection. And thirdly, because the gas conveying capacity is greatly improved, on the basis of ensuring high conveying capacity to a certain degree, the diameter of the gas supply pipeline can be greatly reduced on the basis of the original design specification, and a plurality of flexible pipes with small pipe diameters can be directly connected with a plurality of remote pneumatic devices. A plurality of flexible tubes can be long distance jointless, become the entering user room of bundle cable form, and corresponding pneumatic equipment is connected in the branch again, the construction of being more convenient for like this, and construction cost is lower, and it is lower to the requirement of construction condition, and the effect after the construction is changeed beautifully, safety, practicality, but the reduction that connects simultaneously greatly reduced leaks risk and construction cost. And (IV) because the gas conveying capacity is greatly improved, the gas conveying capacity requirement of the preceding-stage municipal gas conveying pipeline can be reduced to a certain degree, the municipal construction cost is facilitated, or the proper reduction of the gas pressure in the municipal gas conveying pipeline is facilitated, and the gas loss and the safety risk caused by pipeline gas leakage under the unexpected condition are reduced to a certain degree. And (V) the inevitable safe leakage amount of the traditional positive pressure gas supply system in the safety specification is greatly reduced, the safe leakage amount is large in product, the total waste amount is not small, and the energy saving is still considerable although the offset of an emptying and diffusing mechanism exists. And the main system has a simple structure and is simple to construct, and the main negative pressure power sources are dispersed at indoor pneumatic equipment ends, so that the main system has low requirements on site space conditions and is convenient to popularize and implement. If the system of the invention is compared with the traditional system in terms of respective safety risks of defects, explosion occurs under extreme conditions, if air is mixed in the system of the invention and gas in the traditional system is leaked indoors, because the difference between the internal volume of the system and the volume of the indoor room is huge, the damage caused by explosion is completely different from that of the Japanese, the explosion energy of the system is very small, and the degree of damage is controllable. The explosion energy of the indoor space is huge, and the harm caused by the explosion energy is almost uncontrollable.

Example two

The second embodiment also provides an air supply system, the air supply system of the second embodiment describes another implementation scheme of the first valve, and the technical scheme of the first embodiment also belongs to the second embodiment and is not described repeatedly.

As shown in fig. 2, the specific working principle is as follows:

the first valve is a negative pressure air outlet valve 36, and the characteristic that air can be exhausted only when the outlet forms negative pressure is utilized, so that the air supply system can be always kept in a negative pressure state. The specific structure of the negative pressure gas outlet valve 36 can refer to the seventh embodiment or the eighth embodiment.

The negative pressure outlet valve 36 is a mechanical operation structure, and in order to have a sufficient valve opening force, the first pressure setting range is based on the first embodiment, and the lower limit value may be appropriately set while keeping the upper limit value unchanged, and the lower limit value may be-10 KPa, but is not limited thereto.

The negative pressure air outlet valve 36 is provided with a process port 3 at the front and the rear. Because the air outlet of the negative pressure air outlet valve 36 can be opened to ventilate only in the negative pressure state, the front and back process ports 3 of the system in different stages are used when the system is purged by inert gas replacement in the initial operation stage.

After the process port 3 of the negative pressure gas outlet valve 36, all the components are arranged, the functions, the purposes and the like are consistent except for the contents related to the first valve 5, which is the same as the technical scheme of the first embodiment.

Although the second embodiment is not suitable for forming micro negative pressure, the risk of air flowing back into the system is relatively higher than that of the first embodiment due to an accident, but the negative pressure value is not necessarily low, which depends on the area of the diaphragm inside the negative pressure outlet valve 36 and further depends on the volume of the main valve body. In addition, compared with the risk of gas leakage to the indoor environment, the risk of air mixing in the system and the loss caused by accidents are obviously great differences. The second embodiment has the advantage of providing people with an alternative scheme, and the alternative scheme is selected according to comprehensive factors when different situations are met, so that the popularization of the whole system in society is facilitated. The second embodiment has advantages in the case that users are dispersed, the concentration ratio is not high, and a relatively large system is not suitable for construction. It should be noted that in the case of a few users, a low centralized usage, etc., many setting options in the system may also omit the setting, such as the second valve, the third valve, the fourth valve, the fifth valve, the first air storage tank, the first air extraction device, the pressure sensor, the oxygen content sensor, the control unit, the alarm, etc. Because the negative pressure air outlet valve 36 is of a mechanical self-adaptive structure, compared with an electric control electromagnetic valve, the negative pressure air outlet valve has stability or other potential advantages under different conditions. The method is mainly used as a selection item with different forms to adapt to the selection application of various factors and scenes, such as different environmental conditions, practical requirements on safety, cost factors, management factors and the like, so that the method has the existing necessity.

EXAMPLE III

The air supply system in the third embodiment is an improvement on the first embodiment, the technical content disclosed in the first embodiment is not described repeatedly, and the content disclosed in the first embodiment also belongs to the content disclosed in the third embodiment.

As shown in fig. 3, the first air tank 9 is provided with a first air inlet 10 and a first air outlet 11, and the first air outlet 11 is provided in plurality on the first air tank 9.

In the second embodiment, the air supply pipeline has an outdoor section and a plurality of indoor sections, and the outdoor section is communicated with the first air inlet 10; the plurality of indoor sections are respectively communicated with the plurality of first air outlets 11 in a one-to-one correspondence manner.

And a second one-way valve 12 is arranged behind each first air outlet 11, the second one-way valve 12 can be a spring type one-way valve, and the function of the air conditioner is mainly to prevent the room air at normal pressure from flowing backwards to enter the first air storage tank 9 and the outdoor section of the whole system when the indoor section of a user is in an accident situation.

A third valve 13 is arranged behind each second one-way valve 12, and the third valve 13 can be an electromagnetic valve, specifically a normally closed electromagnetic valve; the electric demarcation isolating valve used as a demarcation of the system entering the indoor section is mainly used for automatically cutting off and isolating the outdoor modulating section and the indoor section, and is convenient for the work of construction, debugging, maintenance, repair and the like of the system.

And a second manual valve 14 is arranged behind each third valve 13, is used as a boundary manual isolation valve of the indoor section where the system enters, is mainly used for manually cutting off and isolating the outdoor modulation section and the indoor section, and is convenient for the construction, debugging, maintenance, repair and the like of the system.

Each second manual valve 14 is connected with a branch pipeline to enter the indoor section of the system.

Because the diameter of the gas branch pipe can be relatively small, the gas branch pipe is easy to be connected by adopting a metal or nonmetal flexible pipeline, the construction is convenient, the joints are reduced, and the gas tightness of the gas pipeline is improved.

On several gas branches of the gas supply system and downstream of the third manual valve 27, pneumatic devices are installed, which may be gas devices 28 with a pressure boosting function, or pneumatic devices may be pressure boosting devices 29.

The boosting device 29 can be installed with the traditional gas equipment 30, which is the user gas equipment applied in the system, because the boosting device 29 is arranged between the gas inlet end and the branch pipe of the negative pressure gas supply system, the traditional gas equipment 30 applied in the traditional positive pressure gas supply system can still be applied in the negative pressure gas supply system by virtue of the function of the boosting device 29.

It should be noted that in the second embodiment, the second oxygen sensor 31, the fourth pressure sensor 32, the fifth check valve 33 and the fifth valve 34 may be eliminated from the corresponding indoor section, and the indoor section does not have a main pipe portion, but is composed of branch pipes.

Example four

In a fourth embodiment, an air supply system is provided, which includes: the pneumatic device, the gas supply pipeline and the first valve; the first valve is used for being communicated with an air source and is also communicated with pneumatic equipment through an air supply pipeline; the pneumatic equipment is used for modulating the relative pressure of the gas in the gas supply pipeline, so that the first valve can be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, and the relative pressure of the gas in the gas supply pipeline can be kept within a first pressure setting range.

The number of the pneumatic devices is plural, the number of the first valves may be one or plural, and when the number of the pneumatic devices is plural, the plural pneumatic devices may be provided in one-to-one correspondence with the first valves.

As shown in fig. 4, the first valve is a negative pressure air outlet valve 36, and the air supply system can be always kept in a negative pressure state by utilizing the characteristic that air can be exhausted only when the outlet forms negative pressure. In the embodiment, the number of the branch-pipe-type gas supply pipelines is multiple, and the branch-pipe-type gas supply pipelines are arranged in parallel; the tail end of the gas supply pipeline is communicated with pneumatic equipment through a gas branch pipe; the gas branch pipe can adopt a flexible pipe (the flexible pipe can be metal or nonmetal, and the flexible pipe can be used, but does not exclude a metal hard pipe connection). The specific structure of the negative pressure gas outlet valve 36 can refer to the seventh embodiment or the eighth embodiment.

One or more gas supply pipelines are connected with the gas source pipeline after being connected in parallel, each gas supply pipeline is provided with a first manual valve 2, and the gas supply pipeline is also provided with a negative pressure gas outlet valve 36 at the downstream of the first manual valve; the first manual valve 2 is used for facilitating the operations of installation, disassembly, replacement, stop, maintenance and the like of the negative pressure air outlet valve 36.

The downstream of the negative pressure air outlet valve 36 is correspondingly provided with a second manual valve 14 which is used as a manual isolation valve of the negative pressure air outlet valve 36 on the air supply pipeline, thereby facilitating the work of system construction, debugging, maintenance, repair and the like.

And the gas main pipes are correspondingly connected behind each second manual valve 14 one by one, and gas branch pipes are arranged on the gas main pipes. Because the diameter of the gas branch pipe can be relatively small, the gas branch pipe is easy to be connected by adopting a metal or nonmetal flexible pipeline, the construction is convenient, the joints are reduced, and the gas tightness of the gas pipeline is improved. In this embodiment, the second manual valve 14 is located on the outdoor section.

The gas branch pipe is provided with a fourth one-way valve 26, and the fourth one-way valve 26 is a spring type one-way valve and is used for preventing indoor air from flowing backwards into the system under various accidental conditions of a user gas equipment end.

Pneumatic equipment is respectively arranged on a plurality of gas branch pipes of the gas supply system and is positioned at the downstream of the third manual valve 27, and the pneumatic equipment can be gas equipment 28 with a supercharging function or pneumatic equipment can be a supercharging device 29; the traditional gas equipment 30 is arranged behind the supercharging device 29, which is the user applied gas equipment applied in the system, and because the supercharging device 29 is arranged between the gas inlet end and the branch pipe of the negative pressure gas supply system, the traditional gas equipment 30 applied in the traditional positive pressure gas supply system can still be applied to the negative pressure gas supply system by virtue of the function of the supercharging device 29. The concrete structure of the gas equipment 28 is shown in the fifth embodiment, and the concrete structure of the supercharging device 29 is shown in the sixth embodiment.

The negative pressure outlet valve 36 is a mechanical action structure, and the first pressure setting range is a single value, which may be-10 KPa, in order to have a sufficient valve opening force, but is not limited thereto.

Although it is not desirable to create a slight negative pressure, the risk of air flowing back into the system is relatively high in the event of an accident, but the negative pressure value is not necessarily low, which depends to a large extent on the size of the area of the diaphragm inside the negative pressure outlet valve 36 and thus on the size of the main valve body. In addition, compared with the risk of gas leakage to the indoor environment, the risk of air mixing in the system and the loss caused by accidents are obviously great differences. The fourth embodiment has the advantage of providing people with an alternative scheme, and the selection is carried out according to comprehensive factors when different situations are met, so that the popularization of the whole system in society is facilitated. The fourth embodiment has advantages in the case that users are dispersed, the concentration ratio is not high, and a relatively large system is not suitable for construction. Because the negative pressure air outlet valve 36 is of a mechanical self-adaptive structure, compared with an electric control electromagnetic valve, the negative pressure air outlet valve has stability or other potential advantages under different conditions. The method is mainly used as a selection item with different forms to adapt to the selection application of various factors and scenes, such as different environmental conditions, cost factors, management factors and the like, so that the method has the existing necessity.

EXAMPLE five

The fifth embodiment provides a pneumatic device, which is a gas device 28 with a pressurization function. The gas equipment is a user side gas equipment matched with a gas supply system of gas with negative pressure, normal pressure or micro-positive pressure. The negative pressure air supply system is one of the main negative pressure power sources of the system.

In this embodiment, taking the gas supply system in which the gas is the negative pressure as an example, the gas equipment can modulate the relative pressure of the gas in the system to the negative pressure through the suction end of the second air extraction equipment in the pressurization assembly, and at the same time, can pressurize the gas extracted from the system to any desired pressure value within a certain range according to the design requirement at the outlet end of the gas equipment. Such as: the pressure is increased to the pressure value of the user equipment end commonly used by the traditional positive pressure fuel gas supply system, namely 2KPa +/-10% of natural gas, 2.8KPa +/-10% of liquefied petroleum gas and the like, and the mature technology of the original traditional combustion working condition guarantee mechanism of the fuel gas equipment is used as the technical component of the fuel gas equipment and can be completely continuously applied. In addition, the gas equipment can also pressurize the gas to a higher pressure value, and the limit influence of the fixed value of the gas pressure of the original pipeline is reduced, so that the gas pressure can be directly pressurized at the gas equipment end, and the optimization design of the internal combustion working condition guarantee mechanism of the gas equipment is facilitated by increasing the pressure of the gas on the basis of the prior art. If the thermal load of the gas equipment is certain, when the air is injected and mixed in an injection and suction mode according to the Bernoulli effect principle and by utilizing the Venturi structure, a better mixing effect can be obtained, and as the mixing process is self-adaptive, the mixing device has the advantages of simple structure, stable work, strong reliability, low failure rate and fault rate and good safety, can replace the effect which can be obtained only by blowing the high-thermal-load gas equipment through the blower under the state of a traditional gas supply system to a great extent, and particularly has unique advantages under some special conditions, such as: relatively high gas-fired equipment heat loads, equipment volume limitations, etc. Because the supercharging component is positioned inside the gas equipment, the gas access pipe at the front end of the gas equipment is communicated with the suction end of the second air extraction equipment in the supercharging component, and the part of pipeline cannot be influenced by higher gas pressure to increase the leakage risk.

It should be noted that a fixed gas flow nozzle for controlling the rated heat load of the device can be arranged in the outlet direction of the second air extraction device, and a fixed gas flow nozzle for controlling the rated heat load of the burner and guaranteeing the combustion condition can be arranged at the front end of the burner, so that the gas flow is limited within a certain range, namely the heat load is constant, and the aperture of the fixed gas flow nozzle is small when the gas pressure is high; the aperture of the fixed gas flow nozzle is large when the gas pressure is low, and the gas leakage flow is the same no matter the pressure is high or low, so that the related link can not increase the gas leakage risk of the gas equipment due to higher gas pressure basically, and meanwhile, the formation and application of high-pressure gas in the equipment are linked with the application function of the equipment, and are indirectly protected by a flameout protection device which the gas equipment originally has, namely, the second gas extraction equipment can only be started through manual operation of the linkage device under the condition that the flameout protection device cannot monitor a long open flame, and cannot be started automatically to establish high pressure, so that the risk of gas leakage under an unattended state caused by the fact that the higher pressure gas is applied is not increased to a certain extent. In addition, the gas equipment of the invention not only can be matched and suitable for a negative pressure, normal pressure or micro-positive pressure gas supply system, but also can be separated from the negative pressure, normal pressure or micro-positive pressure gas supply system, and is independently applied to the traditional positive pressure gas supply system, and the gas equipment can be used for pressurizing the gas pressure provided by the traditional positive pressure gas supply system to a higher pressure value in the terminal user gas equipment by utilizing the supercharging function of the traditional positive pressure gas supply system so as to be beneficial to the optimized design of a combustion working condition guarantee mechanism of the gas equipment, and when the gas equipment is mixed by injecting and sucking air, the better mixing effect can be obtained by utilizing the higher gas pressure under the condition of certain heat load of the gas equipment, and as the mixing process is self-adaptive, the gas equipment has simple structure, stability, strong reliability, low failure rate and fault rate and good safety, and can replace a fan gas blowing equipment to a great extent, especially in special conditions, such as relatively high heat load of gas-fired equipment, volume limitation of the equipment and the like. Meanwhile, the application of the gas equipment in the traditional positive-pressure gas supply system can also obviously enhance the gas conveying capacity of the pipeline of the traditional gas supply system, avoid the deterioration of the combustion working condition of the gas equipment caused by the occurrence of the gas deficiency phenomenon, and is beneficial to the stability of the combustion working condition and further the energy conservation and environmental protection. Therefore, the invention can also exert certain performance and effect advantages when being applied to the traditional positive pressure gas supply system.

The pneumatic equipment comprises a sixth valve, second air extraction equipment, a second air storage tank and a seventh valve which are sequentially communicated; the sixth valve is also communicated with the gas supply pipeline.

As shown in fig. 5, the pressure of the pressurized gas is taken as the pressure of the conventional common user equipment, i.e. 2KPa ± 10% for natural gas and 2.8KPa ± 10% for liquefied petroleum gas, for specific description.

The device gas inlet end of the gas device 28 is connected with a third manual valve 27 on the gas branch pipe of the gas supply system in front of the device, so that a gas source is obtained. The gas appliance 28 includes a plenum assembly, a housing, and a combustion device; a plenum assembly 35 is mounted within the housing. The booster assembly 35 provides combustion gases to a combustion device (not shown). The pressure increasing assembly 35 comprises a sixth valve 35.1, a second suction device 35.3, a second air reservoir 35.6 and a seventh valve 35.11. The second suction device 35.3 may be a vacuum/booster pump or other form of power plant with suction/boosting; an eighth valve 35.4 is arranged in parallel with the second suction device. The vacuum/booster pump is a pump with dual functions of vacuum pumping and pressure boosting.

After the third manual valve 27 and the pipeline enters the outer shell of the gas equipment 28, the pipeline of the pressurizing assembly 35 is firstly provided with a sixth valve 35.1, the sixth valve 35.1 is an electromagnetic valve, and the sixth valve 35.1 can be a normally closed electromagnetic valve, which has the main functions that (i) when the equipment is in a non-use state or the second air extraction equipment 35.3 is not in a starting operation state, the sixth valve is in a closed state and is kept to be cut off and isolated from the gas supply system, so that high-pressure gas in the equipment or ambient normal-pressure air accidentally entering the equipment due to the loss of sealing in the equipment flows backward into the negative-pressure gas supply system; when the device is started, in the starting process, a user firstly manually controls a traditional device (such as a gas knob switch on a household gas stove) of the device, then the traditional device is controlled by a linkage device 35.13 and a second control unit 35.12, firstly, the second air extraction device 35.3 is started to operate, when a fifth pressure sensor 35.2 monitors that the gas pressure at the suction end of the second air extraction device 35.3 reaches or is lower than a fourth pressure setting limit value (which can be a single certain set negative pressure value) and is higher than a sixth pressure setting limit value, the second air extraction device is proved to be successfully started and normally operated (at the moment, an eighth valve 35.4 on a bypass pipeline is also normally closed), and at the moment, the sixth valve 35.1 is made to be in a temporary opening state under the manual operation. The fourth pressure setting limit is set in consideration of the problem of ensuring the gas delivery capacity, so that the forward pressure difference between the conventional positive pressure gas supply system and the user gas equipment is usually 2KPa ± 10% in the case of using natural gas as the gas source, and the pressure difference is usually 2.8KPa ± 10% in the case of using liquefied petroleum gas as the gas source, and in consideration of the universality of the equipment for the types of gas, that is, the reference pressure difference is large in the case of using liquefied petroleum gas as the gas source, which is taken as a universal value (to ensure that the gas delivery capacity is sufficient in the case of using natural gas as the gas source), the fourth pressure setting limit is at least lower than-3 KPa, and a certain redundancy is provided in the lower direction on the basis of the universal value, so as to ensure that the fourth pressure setting limit is higher than-3 KPa in the normal automatic operation state after the sixth valve 35.1 is opened, because the second gas extraction device 35.3 has gas from the gas supply system at the gas inlet end, that is, in the state of the conventional positive pressure gas supply system, the gas delivery capacity that can be supported by the pressure difference of 2.8KPa between the positive pressure of 2.8KPa and the normal pressure of 0KPa is equal to the gas delivery capacity that can be supported by the pressure difference of 2.8KPa, which is an absolute value between-0.2 KPa (a lower limit value of the first pressure setting range) and-3 KPa at the gas plant end, in the gas supply pipe of the present negative pressure gas supply system. (because the mass of the fuel gas in the isothermal and isometric state derived according to the gaseous equation is not reduced much, and the mass difference is approximately 1:0.97 and can be ignored according to the comparison calculation of positive 3KPa and-0.2 KPa of the system), the performance parameters such as the maximum air suction capacity of the air suction end, the maximum pressurization capacity of the air outlet end, the flow, the power and the like of the second air suction equipment 35.3 which is used as the type selected by the accessory must meet the corresponding requirements accordingly. On the basis, the lower the fourth pressure setting limit is set, the larger the positive (i.e. along the gas flowing direction) pressure difference value between the gas supply system and the suction end of the second air extraction device 35.3 is, the stronger the pipeline gas conveying capacity is, the smaller the diameter of the gas pipeline of the corresponding gas supply system can be conditionally selected, which is beneficial to the construction of the system, especially in the gas supply system in the form of multi-way branch pipe entering room, the smaller diameter flexible branch pipe pipeline is more beneficial to the construction and subsequent use safety of the system, and the system has stronger practical feasibility; in addition, the setting of the fourth pressure setting limit value is determined by combining the performance parameters of the second air extractor 35.3, the heat load of the gas equipment, the volume of the second air storage tank 35.6 and other factors, so as to avoid the frequent starting of the second air extractor 35.3 caused by the overlarge flow rate in unit time under the overlarge forward pressure difference. The setting of the fourth pressure setting limit, which is preferably, but not exclusively, -10KPa, is used in this example. After the sixth valve 35.1 is opened, the fuel gas entering under the power action of the second air extraction equipment 35.3 or/and the fuel gas remained in the equipment in the last time is ignited by the ignition device, the flameout protection device monitors that the long open fire is effectively ignited, then a signal is input to the second control unit 35.12 through the linkage device 35.13, and under the control of the signal, the sixth valve 35.1 is in an autonomous permanent opening state; (III) when the sixth pressure sensor 35.9 monitors that the pressure of the gas in the second gas storage tank 35.6 rises to 105% or higher than the rated pressure of the user equipment end commonly seen in the conventional positive pressure gas supply system, wherein 105% of the rated pressure of the user equipment end commonly seen in the conventional positive pressure gas supply system is the upper limit value of the fifth pressure setting range, the sixth valve 35.1 is closed under the control of the second control unit 35.12, and the second gas extraction equipment 35.3 also stops running after delay and delay; when the sixth pressure sensor 35.9 monitors that the pressure of the gas in the second gas storage tank 35.6 is reduced to be equal to or lower than 95% of a rated pressure value of a user equipment end common to the conventional positive pressure gas supply system, wherein 95% of the rated pressure value of the user equipment end common to the conventional positive pressure gas supply system is a lower limit value of a fifth pressure setting range, the second gas extraction equipment 35.3 is started to operate under the control of the second control unit 35.12, and meanwhile, the sixth valve 35.1 is also controlled to be opened, it should be noted that the upper limit value and the lower limit value of the fifth pressure setting range are not limited thereto, and if a higher pressure value range can be set so as to adapt to the optimized design of the combustion condition of the gas equipment, and the like; considering that the gas source may be a liquefied gas tank equipped with a negative pressure outlet valve 36, and the user gas equipment is directly connected to the liquefied gas tank, a sixth pressure setting limit (which may be a single certain set negative pressure value) may be set, wherein the negative pressure limit is lower than the fourth pressure setting limit, for example, in the case that the fourth pressure setting limit in this embodiment is preferably-10 KPa, the sixth pressure setting limit in this embodiment is preferably-12 KPa, when the fifth pressure sensor 35.2 detects that the gas pressure at the suction end of the second pumping equipment 35.3 reaches or is lower than the sixth pressure setting limit in the state that the sixth valve 35.1 is opened, it indicates that the gas in the liquefied gas tank is in a non-saturated pressure state and the gas supply capacity is insufficient, and at this time, under the control of the second control unit 35.12, the sixth valve 35.1 is closed, and the second pumping equipment 35.3 is stopped with a delay, and simultaneously, the second alarm device 35.14 is started to give an alarm, and the state is kept until the alarm is manually released, so that the risk that atmospheric air flows backwards into the liquefied gas tank due to the fact that the pressure of the gas in the liquefied gas tank is pumped into a negative pressure state due to transition low-pressure pumping is avoided.

A fifth pressure sensor 35.2 is arranged behind the sixth valve 35.1, and is mainly used for monitoring the pressure value at the suction end of the second air extraction device 35.3 in time in a working state and transmitting a signal to the second control unit 35.12, and further determining the opening and closing of the sixth valve 35.1 and whether the gas equipment is in an operation alarm state according to a fourth pressure setting limit value, or/and a fifth pressure setting range value and a sixth pressure limit value. It should be noted that neither the sixth valve 35.1 nor the fifth pressure sensor 35.2 is a necessary setting option, and without the setting option, the normal use of the main function of the present invention is not affected, and whether the selection is determined by a combination of multiple factors, such as: the manufacturing cost, whether the pressure of the gas supply system is negative pressure or not, whether the gas source is a directly connected liquefied gas tank or not, practical requirements on safety, practical requirements on potential value-added functions such as gas tightness self-detection and the like.

A second air extraction device 35.3 is arranged behind the fifth pressure sensor 35.2, and is mainly used for (I) providing negative pressure power for a gas negative pressure air supply system as a negative pressure power source of the gas negative pressure air supply system; and (II) the power for gas transmission in the gas transmission pipeline between the gas supply system and the gas equipment 28 is used for providing gas for the gas equipment 28 for use. And thirdly, pressurizing the fuel gas obtained from the gas supply system to enable the pressure of the fuel gas to reach an ideal design target value.

Be equipped with the bypass pipeline between second air exhaust equipment 35.3 suction end and the exit end, be equipped with eighth valve 35.4 on the bypass pipeline, the eighth valve is the solenoid valve, the eighth valve can be the normal close type solenoid valve, its main function is, predetermine program control by second control unit 35.12, short time is in the on-state in second air exhaust equipment 35.3 earlier stage of starting operation at every turn, do benefit to the underload start of second air exhaust equipment 35.3, according to predetermineeing the time, wait that second air exhaust equipment 35.3 operates steadily and then close. It should be noted that the eighth valve 35.4 is not a necessary setting option, and whether it is set or not is mainly determined by the designed value of the boost pressure, the start-up load performance of the second pumping device 35.3 itself, and other factors.

And a sixth one-way valve 35.5 is arranged behind the second air extraction device 35.3, and is mainly used for preventing the gas at the high-pressure section in the gas device 28 from flowing backwards and losing pressure when the second air extraction device 35.3 is not started to operate.

Be equipped with second gas holder 35.6 behind sixth check valve 35.5, its main function is that its effect is: the proper volume of the gas storage tank is used for storing a certain amount of gas, the fluctuation frequency of the pressure intensity when the positive pressure gas supply system in the gas equipment 28 works is reduced, the frequent starting times of the second air extraction equipment 35.3 are reduced, meanwhile, the impact of the high-frequency fluctuation of the system pressure intensity on the sixth pressure intensity sensor 35.9 is reduced, and the authenticity and the accuracy of the sixth pressure intensity sensor 35.9 on the monitoring of the pressure intensity of the positive pressure system in the equipment are facilitated. It should be noted that an internal pipe with a certain diameter and length and a sufficiently large volume may also replace the second air tank 35.6 to perform the same function; and (II) the gas-separating cylinder has the function of a gas-separating cylinder, and one or more gas outlets of the gas-separating cylinder can be used as gas source interfaces of one or more burners on one device. In order to deal with the risk of air mixing in the front air supply system of the gas equipment 28 in an extreme accident situation, if a certain volume of equipment internal pipeline is selected to replace the second air storage tank 35.6 of the embodiment, the safety is better, and in an extreme situation, only tempering is always carried out until self-extinguishing, but not explosion.

For convenience of illustration and description, the second air storage tank is selected, and one second air storage tank or a plurality of second air storage tanks connected in parallel are strictly and reasonably selected according to the thermal load condition of the equipment, so that the volume of a single second air storage tank can be controlled, and further the risk of explosion of the container can be controlled, because the reason that the explosion gas-air ratio limit can be formed is as follows: the explosion limit of natural gas is 5% -15%, the explosion limit of liquefied petroleum gas is 1.7% -9.7%, the gas quantity in the second gas storage tank with reasonable volume capable of forming explosion concentration is much less than the air quantity, and the energy of the small gas quantity is small and controllable even if the explosion happens in extreme conditions.

The second air storage tank 35.6 is provided with a second air inlet 35.7 and a second air outlet 35.8, and the arrangement of the second air outlet 35.8 on the second air storage tank 35.6 can be one or more. The second outlet 35.8 can be a flow restriction outlet, which can be a nozzle with a fixed aperture, and the flow restriction outlet can be a nozzle with a fixed aperture, and the flow restriction nozzle can limit the gas flux according to the pressure target value designed by the device and the total heat load of the burner loaded by the outlet.

The second gas storage tank 35.6 is provided with a sixth pressure sensor 35.9, which is used for monitoring the pressure of the gas in the second gas storage tank 35.6 and transmitting the pressure to the second control unit 35.12 in real time.

The second air storage tank 35.6 is provided with a third pressure relief device 35.10 which is used for timely removing the pressure protection container and equipment when accidental high pressure such as internal tempering, explosion and the like occurs in the second air storage tank 35.6 container or system.

The third pressure relief device 35.10 is of a one-time explosion open type (such as a pressure rupture diaphragm type) when meeting overpressure, and is provided with an action detection electric device, when the third pressure relief device acts when meeting overpressure, an electric signal is transmitted to the second control unit 35.12, the gas equipment 28 stops normal operation under the control of a preset program of the second control unit 35.12, the sixth valve 35.1 is forcibly closed and kept, meanwhile, the second alarm device 35.14 is started to give an alarm, and the state is still kept even if power is lost and then powered up until the state is recovered after manual repair.

A seventh valve 35.11 is arranged behind the second gas storage tank 35.6, the seventh valve 35.11 is an electromagnetic valve, the seventh valve can be a normally closed electromagnetic valve, and its main function is that (a) is controlled by the second control unit 35.12, when the sixth pressure sensor 35.9 monitors that the pressure of the gas in the second gas storage tank 35.6 rises to 110% or higher than the rated pressure of the user equipment end commonly seen in the conventional positive pressure gas supply system, wherein 110% of the rated pressure of the user equipment end commonly seen in the conventional positive pressure gas supply system is the upper limit value of the seventh pressure setting range, or when the sixth pressure sensor 35.9 monitors that the pressure of the gas in the second gas storage tank 35.6 falls to 90% or lower than the rated pressure of the user equipment end commonly seen in the conventional positive pressure gas supply system, wherein 110% of the rated pressure of the user equipment end commonly seen in the conventional positive pressure gas supply system is the lower limit value of the seventh pressure setting range, the seventh valve 35.11 is closed in time under the control of the second control unit 35.12; only when the sixth pressure sensor 35.9 monitors that the pressure of the gas in the second gas storage tank 35.6 is kept within the seventh pressure setting range, the seventh valve 35.11 can be opened along with the application of a user under the control of the second control unit 35.12, so that the stability of the combustion working condition of the burner arranged on the gas equipment 28 is ensured, and the danger that the environment pollution and the energy waste are caused by insufficient combustion of the burner or the gas is directly leaked due to the fact that the burner cannot combust is avoided. It should be noted that the upper limit value and the lower limit value of the seventh pressure setting range are not limited thereto, and for example, it is also possible to consider setting a higher pressure value range to adapt to the optimization design of the combustion condition of the gas equipment. And (II) when the equipment stops working, the seventh valve 35.11 is closed, the supply of the residual gas in the second gas storage tank 35.6 to the subsequent combustion working condition guarantee mechanism is cut off, the gas tightness of the equipment in a standby state is enhanced, and meanwhile, the residual gas in the second gas storage tank 35.6 is beneficial to timely obtaining the gas when the equipment is used again next time so as to ignite long-time naked flames.

The seventh valve 35.11 is followed by a combustion device, which is prior art and which is not described in detail in this embodiment. It should be noted that although the combustion equipment part connected after the seventh valve 35.11 is the prior art, because of the benefit of the present invention, the pressure of the gas can be obtained by the pressure boosting assembly 35, which is higher and more ideal than the conventional one, so that some new related technologies can be derived optimally, such as: gas/air premixing related technologies, new high-efficiency burner related technologies, and the like. Or/and by the combination of the control part of the prior art with the second control unit 35.12 of the invention, and the related facilities of pressure sensors, solenoid valves, etc., some new or potential functions are optimized or derived, such as: the gas-fired switch and adjusting device, flame-out protection device, gas tightness self-detection, working state monitoring, working data statistics and recording, intelligent control and the like.

The second control unit 35.12 is arranged in the gas equipment 28, and is used for comprehensively controlling the operation of the equipment, and meanwhile, the self-detection function of timing and pressure maintaining of the air tightness of the equipment and other potential expansion functions can be designed according to requirements and necessities.

The linkage 35.13 is arranged behind the second control unit 35.12, the linkage 35.13 is connected with the combustion equipment, and the linkage functions as the necessary function linkage of the invention and the traditional gas equipment. The linkage 35.13 may be in the form of an electrical or mechanical device or a combination of an electrical and mechanical device. Such as when a person operates a knob switch in the conventional form of a gas appliance, the action of which may be transmitted to the second control unit 35.12 via linkage 35.13 to cause the control unit 35.12 to react accordingly and perform the associated control.

The second control unit 35.12 is provided with a second alarm 35.14, which is controlled by the second control unit 35.12 to alarm when various accidents need to be alarmed, and can transmit the alarm signal remotely. The second warning device 35.14 may also be provided with the necessary information for the operating status.

EXAMPLE six

The embodiment provides a pneumatic device, the pneumatic device is a pressure increasing device 29, the pressure increasing device 29 is different from the gas device 28 in the fifth embodiment in that the pressure increasing device 29 does not include a combustion device, and the gas device 28 includes a combustion device, except that the technical solution described in the fifth embodiment also belongs to the sixth embodiment, and the technical solution described in the fifth embodiment is not described repeatedly.

The supercharging device 29, which is first of all a supercharging device that is matched with a negative pressure, normal pressure or micro-positive pressure gas supply system, is a supercharging device that can be normally applied to the three gas supply systems by the conventional gas equipment 30. For a gas supply system, it is one of the main negative pressure power sources of the gas supply system.

As shown in fig. 6, the seventh valve 35.11 of the pressure boosting device 29 is connected to a conventional gas appliance 30. Linkage 35.13 functions to: under the condition (for example, the conventional gas appliance 30 is a large-scale commercial cooker or an industrial gas appliance), the linkage of necessary functions with the conventional gas appliance 30 can be realized. The linkage 35.13 may be in the form of an electrical or mechanical device or a combination of an electrical and mechanical device. The linked signal device 35.13 is connected to the conventional gas appliance 30.

EXAMPLE seven

The embodiment of the invention also provides a negative pressure air outlet valve which is applied to the air supply systems provided by the second embodiment and the fourth embodiment.

The first valve is a negative pressure air outlet valve, the negative pressure air outlet valve comprises a main valve body, a valve plate, a diaphragm and an open valve ejector rod, and the main valve body is provided with a normal pressure chamber, a positive pressure air inlet chamber and a negative pressure air outlet chamber; the positive pressure air inlet chamber is communicated with a positive pressure air inlet, and the negative pressure air outlet chamber is communicated with a negative pressure air outlet; the valve plate is arranged in the positive pressure air inlet chamber, two stages of sealing ring areas with different diameters are coaxially arranged on the valve plate, the sealing ring area with the small diameter on the valve plate is a first-stage sealing ring area, and the sealing ring area with the large diameter on the valve plate is a second-stage sealing ring area; the valve plate can close a valve port communicated between the positive pressure air inlet chamber and the negative pressure air outlet chamber under the common action of a valve plate spring and the air pressure of the positive pressure air inlet chamber; the valve port is coaxially provided with two stages of sealing ring areas corresponding to the valve plate, the sealing ring area with the small diameter on the valve port is a first-stage sealing ring area, and the sealing ring area with the large diameter on the valve port is a second-stage sealing ring area; the diaphragm is fixedly connected with the valve opening ejector rod, the normal pressure chamber and the negative pressure air outlet chamber are separated by the diaphragm, when the relative pressure of air in the negative pressure air outlet chamber is lower than that of air in the environment outside the main valve body by a certain value, the diaphragm can apply certain valve opening force to the valve opening ejector rod in the valve opening direction under the action of pressure difference, and when the force is large enough, the diaphragm can drive the valve opening ejector rod to move so as to overcome the valve closing pressure formed by the valve plate spring and the pressure of the air in the positive pressure air inlet chamber, so that the valve plate moves in the valve opening direction and the valve port is opened; under the normal working state, only the first-stage sealing ring area of the valve plate contacts with the first-stage sealing ring area of the valve port to play a role of sealing and closing the valve port, and the second-stage sealing ring area of the valve plate does not contact with the second-stage sealing ring area of the valve port, so that the valve port cannot be sealed and closed, when the first-stage sealing ring area of the valve plate gradually ages and fails, before the valve completely fails, the second-stage sealing ring area of the valve plate contacts with the second-stage sealing ring area of the valve port to play a role of sealing and closing the valve port, at the moment, the diameter of the valve plate and the diameter of the valve port sealing area are increased correspondingly, under the condition that the pressure intensity of gas in the positive pressure gas inlet cavity is equal, the sealing pressure of the valve plate under the pressure intensity of the gas in the positive pressure gas inlet cavity is increased correspondingly, so that the valve opening force of the valve ejector rod driven by the diaphragm under the same working condition is, therefore also lead to the valve port can not normally open to play on safe basis with can not normally work as the expression form, remind the effect of early warning to sealing failure.

As shown in fig. 7, the structure of the negative pressure air outlet valve 36 is composed of the following parts:

the main valve body 36.1, which functions as the main structure of the negative pressure outlet valve 36, undertakes the connection of the main chamber structure and other valve body parts and the mounting and fixing base.

The main valve body 36.1 is provided with an air inlet end connecting flange 36.2 which is used for connecting with a traditional positive pressure gas supply system to obtain the gas output by the traditional positive pressure gas supply system.

The back of the air inlet end connecting flange 36.2 is provided with a positive pressure air inlet 36.3, the caliber of which is matched with the specification of a general pipeline of a gas pipeline project according to the rated gas design flux of the negative pressure air outlet valve 36, such as: for example, the specification of matched DN65 is set, and the fuel gas flux of the valve body is also matched with the specification of DN 65.

The back of the positive pressure air inlet 36.3 is provided with a positive pressure air inlet chamber 36.4, a valve plate 36.5 is arranged in the chamber, a sealing structure 36.6 is coaxially arranged on the valve plate 36.5, the sealing structure 36.6 is fixed on one side of the valve plate 36.5, which is axially close to the valve port 36.8, and the valve plate 36.5, the sealing structure 36.6, a valve plate spring 36.7, the valve port 36.8 and a sealing port 36.9 are coaxially arranged. The sealing structure can be made of rubber or other materials, and can be a sealing ring.

As shown, the valve plate 36.5 is fixed to the upper end of the valve plate spring 36.7, and the lower end of the valve plate spring 36.7 is fixed to the bottom of the positive pressure intake chamber 36.4. The valve plate 36.5 is used for applying a certain positive valve closing pressure to one side of the valve port 36.8 under the combined action of a valve plate spring 36.7 and the gas pressure in the positive pressure gas inlet chamber 36.4, forming a sealed valve closing state (namely a first-stage sealing ring area forms a seal) between the sealing structure 36.6 and the sealing port 36.9, and cutting off the gas in the positive pressure gas inlet chamber 36.4 from being output to the negative pressure gas outlet chamber 36.10 through the valve port 36.8; when the valve plate 36.5 is subjected to reverse valve opening force action from the valve opening mandril 36.15 in the negative pressure air outlet cavity 36.10 and the reverse valve opening force is larger than forward valve closing pressure formed by the combined action of the valve plate spring 36.7 and the gas pressure in the positive pressure air inlet cavity 36.4, the valve plate 36.5 and the sealing structure 36.6 are subjected to reverse valve opening force action and move towards the side far away from the valve port 36.8, so that the sealing valve closing state between the sealing structure 36.6 and the sealing port 36.9 is released (namely the sealing of the primary sealing ring area is released), and the valve closing state is changed into the valve opening state; when the reverse valve opening force is smaller than the normal valve closing pressure again, the valve closing state is restored again, and the valve is dynamically and cyclically operated.

A valve port 36.8 is arranged in the positive pressure air inlet chamber 36.4, the air inlet end of the valve port 36.8 is communicated with the positive pressure air inlet chamber 36.4, the air outlet end is communicated with the negative pressure air outlet chamber 36.10, and the caliber of the valve port is matched with the rated gas flux of the negative pressure air outlet valve 36.

The radial edge of the air inlet port of the valve port 36.8 is provided with a sealing port 36.9, the annular sealing port 36.9 forms a primary sealing ring area, and the effect of the sealing ring area is to increase the contact pressure with the sealing structure 36.6 by utilizing the circular arc bulge which is annular and relatively sharp, thereby enhancing the sealing effect when the valve is closed. The sharpness, sharp angle, and protrusion height also take into account that the durability of the seal structure 36.6 should not be too sharp, leading to rapid failure of the seal structure 36.6.

A negative pressure air outlet chamber 36.10 is arranged at the air outlet end of the valve port 36.8, a semi-closed partition wall 36.11 is arranged in the chamber, and the chamber is divided into an upper compartment and a lower compartment by the partition wall as seen in the figure. The upper end face of the partition wall, namely one face facing the upper separation chamber, is in a conical shape with a large-diameter end up and a small-diameter end down, and the partition wall is provided with a plurality of vent holes so as to be beneficial to the dynamic balance of the pressure in the upper separation chamber and the lower separation chamber.

The top of the upper compartment is a diaphragm 36.12, and the diaphragm 36.12 is made of rubber; an atmospheric pressure chamber 36.13 is arranged above the upper compartment, and the upper compartment and the atmospheric pressure chamber 36.13 are separated by a diaphragm 36.12. The diaphragm 36.12 mainly functions as a sealing and isolating member between the negative pressure gas outlet chamber 36.10 and the normal pressure chamber 36.13, and when negative pressure is generated in the negative pressure gas outlet chamber 36.10, the diaphragm 36.12 functions as a force/application element to drive the valve opening ejector 36.15 to move downwards to realize valve opening action under the action of pressure difference between atmospheric pressure in the normal pressure chamber 36.13 and negative pressure of gas in the negative pressure gas outlet chamber 36.10 and the pressure formed by the influence of the pressure difference and the diaphragm fixing area factor, namely when the reverse valve opening force is greater than the forward valve closing force applied to the valve plate 36.5.

A certain spacing size is designed between the upper end surface of the partition wall 36.11 in the upper compartment and the diaphragm 36.12 in a valve closing state, the spacing size determines the maximum opening degree of the valve plate 36.5, the opening degree is matched with the gas design flux of the valve port, the maximum opening degree is calculated by referring to the diameter of the sealing port 36.9, the valve opening mandril 36.15 or the connecting rod 36.20, and the upper end surface of the partition wall 36.11 is used as the limit of the diaphragm 36.12 to prevent the diaphragm 36.12 from being damaged due to overlarge valve opening movement amplitude.

An open valve ejector 36.15 and an ejector guide sleeve 36.16 are arranged in the lower compartment.

The upper end of the valve opening ejector 36.15 is fixedly connected with the diaphragm 36.12, and the ejector guide sleeve 36.16 is fixed on the inner wall of the lower chamber (shown as the bottom of the inner wall) through a fixing bracket 36.24. The lower end of the valve opening ejector rod 36.15 is hemispherical, and the hemispherical lower end is in non-fixed contact with the valve plate 36.5, so that the radial and axial angles of the valve plate 36.5 have certain spatial movement freedom, good contact between the sealing structure 36.6 and the sealing opening 36.9 is facilitated, and the sealing effect is further ensured.

A compartment air outlet 36.17 is arranged in the lower compartment, and a compartment air outlet 36.17 is used as a negative pressure gas outlet in the negative pressure air outlet chamber 36.10 and is communicated with a negative pressure air outlet 36.18 arranged on the main valve body 36.1. The gas flux of the compartment gas outlet 36.17 and the negative pressure gas outlet 36.18 is matched with the rated gas design flux of the negative pressure gas outlet valve 36.

In the direction shown in the figure, the normal pressure chamber 36.13 is arranged above the diaphragm 36.12, the sealing cover 36.14 is arranged above the normal pressure chamber 36.13, the sealing cover 36.14 is connected with the main valve body 36.1 through a fixing screw, the diaphragm 36.12 is clamped between the lower end face of the sealing cover at the connection part and the upper end face of the main valve body, and the main valve body 36.1, the diaphragm 36.12 and the sealing cover 36.14 are tightly sealed and fixed through the rubber sealing function of the diaphragm 36.12 and the fastening function of the fixing screw. The sealing cover 36.14 is provided with a balance breathing hole with a filter device to communicate with the atmosphere outside the main valve body, when the diaphragm 36.12 is forced to move to change the space volume in the normal pressure chamber 36.13, the air pressure in the normal pressure chamber 36.13 can be kept to be dynamically balanced with the ambient atmosphere through the balance breathing hole.

Meanwhile, the normal pressure chamber 36.13 also plays a role in protecting and preventing dust for the upper movable area of the diaphragm 36.12 through the sealing cover 36.14.

The main valve body 36.1 is also provided with a negative pressure air outlet 36.18, the caliber of which is matched with the specification of a general pipeline of a gas pipeline project according to the rated gas design flux of the negative pressure air outlet valve 36, and if the matched pipe diameter is set to be DN65 specification, the gas flux of the valve body is also matched with DN65 specification.

The negative pressure air outlet 36.18 is provided with an air outlet end connecting flange 36.19 which is used for connecting with a negative pressure air supply system to output fuel gas in a negative pressure mode.

It should be noted that, the structural mode among the valve opening ejector pin 36.15, the valve plate 36.5 and the valve plate spring 36.7 of the negative pressure air outlet valve can be another scheme, namely, the valve opening ejector pin 36.15 acts on the valve plate 36.5 through the connecting rod 36.20; as shown in fig. 8, the valve plate spring 36.7 is disposed in the negative pressure outlet chamber 36.10, as shown in fig. 8, the lower end of the valve plate spring 36.7 is fixed at the bottom of the inner wall of the negative pressure outlet chamber 36.10, the spring force is applied to the valve plate 36.5 through the connecting rod 36.20, the lower end of the connecting rod 36.20 and the valve plate 36.5 may be connected in a ball hinge manner, the upper end of the connecting rod 36.20 is fixed with a disc, and the lower end surface of the disc is in non-fixed contact with the upper end of the valve plate spring 36.7.

As shown in fig. 9, fig. 9 is an enlarged detail view of the position of the valve plate 36.5 in fig. 7, the upper end of the outer diameter of the valve plate 36.5 is provided with a conical surface 36.21, a circumferential groove is formed on the conical surface 36.21, an annular sealing structure 36.22 is arranged in the groove, and the sealing structure 36.22 forms a secondary sealing ring area; the sealing structure can be made of rubber or other materials, and can be a sealing ring. The conical valve port 36.23 is arranged above the conical surface 36.21, namely at the periphery of the sealing port 36.9 of the valve port 36.8, and under the normal condition, a certain gap a is left between the inner conical surface and the outer conical surface of the conical surface 36.21, which is a protective valve port, and the gap a does not play a role in sealing and isolating the gas from passing through during normal operation, however, when the sealing structure 36.6 on the valve plate 36.5 is over-long, the position of the valve plate 36.5 in the valve-closed state will gradually move upward than normal along with the change of the failure trend, and further the conical surface 36.21 will gradually move upward along with the change of the failure trend, and when the conical surface 36.21 moves upward to a certain position, when the sealing structure 36.6 is about to fail, the conical surface 36.21 on the valve plate 36.5 and the sealing structure 36.22 are acted by the valve plate spring 36.7 and the gas pressure of the gas in the positive pressure inlet chamber 36.4, and the conical valve port 36.23, thereby avoiding the uncontrolled flow of positive pressure gas to a negative pressure gas supply system caused by the failure of the sealing structure 36.6. Because the diameter of the annular sealing structure 36.22 is the sealing diameter of the conical valve port 36.23, the diameter is much larger than the diameter of the sealing port 36.9, and the effective pressure area of the corresponding valve plate 36.5 under the action of the positive pressure air inlet chamber gas pressure is many times larger, the valve closing force obtained by the valve plate 36.5 is increased, so that the valve opening force of the valve opening mandril 36.15 driven by the diaphragm 36.12 under the same working condition is insufficient to enable the valve plate 36.5 to overcome the valve closing force and move towards the valve opening direction, and the valve port cannot be normally opened to cut off the gas delivery, thereby taking the abnormal working as an expression form on the basis of safety, reminding and early warning the sealing failure, achieving the purpose of reminding and maintaining and replacing the sealing structure 36.6, and ensuring the safe operation of the system. The size of the clearance a is adjusted in the design to ensure that the sealing of the cone-shaped valve port 36.23 is effectively activated before the sealing performance of the seal 36.6 fails, according to the fatigue test of the selected seal 36.6. Fig. 10 shows the open state of the negative pressure outlet valve 36, and the reasonableness of arrangement of the components in the main valve body in terms of spatial position will be described.

Example eight

The embodiment of the invention also provides another negative pressure gas outlet valve which is mainly applied to connection between a dispersed and independent liquefied petroleum gas tank (hereinafter referred to as a liquefied gas tank) and gas equipment, and can also be applied to the condition that a front-end gas source of a gas supply system provided by the second embodiment and the fourth embodiment is the liquefied gas tank. It should be noted that the existing liquefied gas tank can be simply modified, or/and the liquefied gas tank can be redesigned and manufactured, and a new device is formed by the liquefied gas tank and the negative pressure gas outlet valve, so as to replace the existing traditional liquefied gas tank.

The negative pressure air outlet valve comprises a main valve body, a valve plate, a diaphragm and an open valve ejector rod, wherein the main valve body is provided with a normal pressure chamber, a positive pressure air inlet chamber and a negative pressure air outlet chamber; the positive pressure air inlet chamber is communicated with a positive pressure air inlet, and the negative pressure air outlet chamber is communicated with a negative pressure air outlet; the valve plate is arranged in the positive pressure air inlet chamber, two stages of sealing ring areas with different diameters are coaxially arranged on the valve plate, the sealing ring area with the small diameter on the valve plate is a first-stage sealing ring area, and the sealing ring area with the large diameter on the valve plate is a second-stage sealing ring area; the valve plate can close a valve port communicated between the positive pressure air inlet chamber and the negative pressure air outlet chamber under the common action of a valve plate spring and the air pressure of the positive pressure air inlet chamber; the valve port is coaxially provided with two stages of sealing ring areas corresponding to the valve plate, the sealing ring area with the small diameter on the valve port is a first-stage sealing ring area, and the sealing ring area with the large diameter on the valve port is a second-stage sealing ring area; the diaphragm is fixedly connected with the valve opening ejector rod, the normal pressure chamber and the negative pressure air outlet chamber are separated by the diaphragm, when the relative pressure of air in the negative pressure air outlet chamber is lower than the relative pressure of air in the environment outside the main valve body by a certain value, the diaphragm can apply certain valve opening force to the valve opening ejector rod in the valve opening direction under the most use of pressure difference, and when the force is large enough, the diaphragm can drive the valve opening ejector rod to move so as to overcome the valve closing pressure formed by the pressure of air in the valve plate spring and the positive pressure air inlet chamber together, so that the valve plate moves in the valve opening direction and the valve port is opened; under the normal working state, only the first-stage sealing ring area of the valve plate contacts with the first-stage sealing ring area of the valve port to play a role of sealing and closing the valve port, and the second-stage sealing ring area of the valve plate does not contact with the second-stage sealing ring area of the valve port, so that the valve port cannot be sealed and closed, when the first-stage sealing ring area of the valve plate gradually ages and fails, before the valve completely fails, the second-stage sealing ring area of the valve plate contacts with the second-stage sealing ring area of the valve port to play a role of sealing and closing the valve port, at the moment, the diameter of the valve plate and the diameter of the valve port sealing area are increased correspondingly, under the condition that the pressure intensity of gas in the positive pressure gas inlet cavity is equal, the sealing pressure of the valve plate under the pressure intensity of the gas in the positive pressure gas inlet cavity is increased correspondingly, so that the valve opening force of the valve ejector rod driven by the diaphragm under the same working condition is, therefore also lead to the valve port can not normally open to play on safe basis with can not normally work as the expression form, remind the effect of early warning to sealing failure.

As shown in fig. 11, the negative pressure outlet valve may also be referred to as a negative pressure outlet combination valve, and the negative pressure of the negative pressure outlet combination valve 37 is derived from the gas appliance 28, or/and the pressure boosting device 29. As shown, the main valve body 37.1 of the negative pressure outlet combination valve 37 is a main structural component, which carries and connects other related components together, the inlet end of the main valve body is connected with the liquefied gas tank, and the outlet end is connected with the user gas equipment, i.e. the outlet end is connected with the gas equipment 28 or/and the pressure boosting device 29. The gas in the liquefied gas tank enters the valve body through the positive pressure gas inlet 37.2, and then enters the manual valve chamber 37.4 through the first communication conduit 37.3 arranged at the upper end of the positive pressure gas inlet 37.2, and the manual valve 37.5 is in a manual closing state when the gas equipment is not used temporarily or in the process of filling and transporting the liquefied gas tank. The gas is correspondingly circulated or stopped under the control of opening or closing of the manual valve 37.5, if the manual valve 37.5 is in an open state, the gas enters the positive pressure gas inlet chamber 37.7 through the second communication conduit 37.6, a valve plate spring 37.8 and a valve plate 37.9 are arranged in the positive pressure gas inlet chamber 37.7, the lower end of the valve plate spring 37.8 is fixed at the bottom of the positive pressure gas inlet chamber, the upper end of the valve plate spring is fixed at the valve plate 37.9, a sealing structure 37.10 is arranged on the valve plate 37.9, the sealing structure can be made of rubber or other materials, and can be a sealing ring. The upper end of the positive pressure air inlet chamber 37.7 is provided with a valve port 37.11, the valve port 37.11, a valve plate 37.9 and a valve plate spring 37.8 are coaxially arranged, the lower end of the valve port 37.11, namely a fuel gas inlet end of the valve port, is provided with a convex sealing port 37.12 along the circumference of the port, the valve plate 37.9 presses the lower end of the valve port 37.11 under the action of valve closing force formed by the valve plate spring 37.8 and the pressure of positive pressure fuel gas, fuel gas is stopped at the position of the positive pressure air inlet chamber 37.7 through contact sealing between a sealing structure 37.10 and the sealing port 37.12, and the valve plate 37.9 is in a closed valve shape. The upper end of the valve port 37.11, namely the air outlet end of the valve port 37.11, is provided with a negative pressure air outlet cavity 37.13, a secondary lever 37.14 is symmetrically arranged in the negative pressure air outlet cavity 37.13, the secondary lever 37.14 is fixed at the bottom of the negative pressure air outlet cavity 37.13 through a fulcrum support, one end of the secondary lever 37.14 close to the symmetry axis, namely the force application end of the valve opening force, is designed in a tuning fork-shaped clamp plate shape, and is provided with a long circular hole, a valve opening mandril 37.15 is connected through a connecting shaft, the valve opening mandril 37.15 is coaxially arranged with the valve port 37.11, the secondary lever 37.14 is an equi-force arm lever, the fulcrum is arranged at the center position of the force application end and the force application end (the design example is the same, but not limited to the design example), mainly plays a role of changing the force application direction, one end of the secondary lever 37.14 far away from the symmetry axis, namely the force application end of the valve opening force application end is provided with a circular hole, a movable lifting ring 37.16 is connected with, the primary lever 37.17 is fixed at the bottom of the negative pressure air outlet cavity 37.13 through a fulcrum support, one end of the primary lever 37.17 close to a symmetrical axis, namely a force bearing end for opening a valve force, is designed in a tuning fork-shaped splint type, is provided with a long round hole, is connected with a diaphragm component 37.18 through a connecting shaft, the diaphragm component 37.18 is arranged coaxially with a valve port 37.11, the primary lever 37.17 is a labor-saving lever, the fulcrum is close to the force bearing end, and the distance between the force bearing end and the fulcrum is 4 times of the distance between the force bearing end and the fulcrum, namely 2 cm: 0.5cm (this design example is, but not limited to this), mainly playing a role in increasing torque, the diaphragm assembly 37.18 is tightly and fixedly connected with the diaphragm 37.19, the diaphragm 37.19 is made of rubber, the diaphragm 37.19 mainly functions as a sealing and isolating member between the negative pressure air outlet chamber 37.13 and the normal pressure chamber 37.20, meanwhile, when negative pressure is generated in the gas in the negative pressure air outlet chamber 37.13, the diaphragm 37.19 is influenced by the pressure difference between the atmospheric pressure in the normal pressure chamber 37.20 and the negative pressure of the gas in the negative pressure air outlet chamber 37.13, and when the valve opening force formed by the influence of the pressure difference and the diaphragm fixed area factor is larger than the valve closing force of the valve plate 36.5 by the forcing action of the primary lever 37.17, the diaphragm 37.19 functions as a force-receiving/applying element, and the valve opening force is driven by the diaphragm assembly 37.18, the primary lever 37.17, the movable hanging ring 37.16 and the secondary lever 37.14 to move the valve opening 37.15 downwards. A normal pressure chamber 37.20 is arranged above the diaphragm 37.19, a sealing cover 37.21 is arranged above the normal pressure chamber 37.20, the sealing cover 37.21 is connected with the main valve body 37.1 through a fixing screw, the diaphragm 37.19 is clamped between the lower end face of the sealing cover at the connection part and the upper end face of the main valve body, and the main valve body 37.1, the diaphragm 37.19 and the sealing cover 37.21 are tightly sealed and fixed through the rubber sealing effect of the diaphragm 37.19 and the locking effect of the fixing screw. The sealing cover 37.21 is provided with a balance breather hole with a filter device to communicate with the atmosphere outside the valve body, when the diaphragm 37.19 is forced to move to change the space volume in the normal pressure chamber 37.20, the air pressure in the normal pressure chamber 37.20 can be kept dynamically balanced with the ambient atmosphere through the balance breather hole.

Meanwhile, the normal pressure chamber 37.20 also plays a role in protecting and preventing dust for the upper movable area of the diaphragm 37.19 through the sealing cover 37.21.

The main valve body 37.1 is further provided with a negative pressure gas outlet 37.23 which is communicated with the negative pressure gas outlet chamber 37.13 through a third communication conduit 37.22, and a negative pressure gas outlet 37.23 which is used as an interface connected with a user gas equipment end, in consideration of the universality of the interface with a traditional connecting piece, the interface design of the negative pressure gas outlet 37.23 in the design example is matched with the outlet connecting piece of a traditional liquefied gas tank, and the connecting thread of the output end interface is left-handed, but the invention is not limited to the left-handed thread, and can be changed into any other interface form according to the requirements, such as a fast-assembly interface, or/and the interface form of connecting a flexible hose with smaller diameter and more durability.

The negative pressure air outlet 37.23 is connected with the user gas equipment, that is, the user gas equipment can be the gas equipment 28 or/and the supercharging device 29, when the user starts the gas equipment, the negative pressure generated by the gas equipment acts on the negative pressure air outlet chamber 37.13 through the negative pressure air outlet 37.23 and the third communication conduit 37.22, the negative pressure generated by the equipment is-10 KPa, at the moment, the pressure difference with the absolute value of 10KPa is formed between the negative pressure air outlet chamber 37.13 and the normal pressure chamber 37.20, and the pressure difference acts on the upper surface of the diaphragm 37.19 to press the diaphragm 37.19 and the diaphragm assembly 37.18 to move downwards.

Fig. 12 is a left side view (in cross section) of a negative pressure air outlet valve provided in the eighth embodiment of the present invention; as shown in the figure, a filling port 37.24 is arranged on the valve body and is a filling port of the liquefied petroleum gas tank, a sealing plug 37.25 is arranged on the filling port 37.24, the filling port 37.24 is plugged and sealed by the sealing plug 37.25 in the normal use state of the liquefied gas tank or in the transportation process of the liquefied gas tank, before filling operation, the sealing plug 37.25 is firstly removed, and after filling operation, the sealing plug 37.25 is installed and sealed to prevent gas leakage in the tank. The sealing plug 37.25 is provided with two radial and axial rubber sealing rings, so that good air tightness is ensured, disassembly and assembly are facilitated, and meanwhile, the sealing structure is convenient to replace at any time. The seventh check valve 37.26 is coaxially arranged in the filling port 37.24, the seventh check valve 37.26 is a spring type check valve, the liquefied petroleum gas in the tank cannot be discharged automatically when the sealing plug 37.25 is removed, and only when a special ejector rod is arranged on a special filling gun port matched with the tank, the seventh check valve 37.26 can be opened under the action of the special ejector rod, so that filling and filling are facilitated. The axial vertical direction behind the seventh one-way valve 37.26 is communicated with the positive pressure air inlet 37.2, namely, one end of the one-way valve far away from the sealing plug 37.25 is communicated with the positive pressure air inlet 37.2. The filled liquefied petroleum gas is thus reversed into the liquefied gas tank.

Fig. 13 is a left side view (cross section) of another modified structure of the negative pressure outlet valve provided in the eighth embodiment of the present invention, which is different from fig. 12 in that: in fig. 13, the filling port 37.24 is fitted with an in-line valve 37.27. As shown in fig. 13, a filling port 37.24 is provided on the valve body, which is a filling port of the liquefied gas tank, a through valve 37.27 having the same specification but different form as an angle valve fixedly fitted on a conventional liquefied gas tank is provided on the filling port 37.24, and then the through valve is communicated with the positive pressure gas inlet 37.2 through a communication conduit 37.28, so that the filled liquefied petroleum gas reversely enters the liquefied gas tank. In normal use or during transportation of the tank, the through valve 37.27 is closed, which is only used for filling liquefied petroleum gas, as an alternative or as a temporary transitional option to accommodate established conventional practices and tools, and is not preferred, but indirectly enhances the practical feasibility of the overall negative pressure system implementation.

Fig. 14 is an enlarged view of the valve plate 37.9, in which the upper end of the outer diameter of the valve plate 37.9 is provided with a conical surface 37.28, a circumferential slot is formed on the conical surface 37.28, an annular sealing structure 37.29 is arranged in the slot, the sealing structure may be made of rubber or other materials, and the sealing structure may be a sealing ring. A conical valve port 37.30 is arranged above the conical surface 37.28, namely at the periphery of the circumference of the sealing port 37.12, a certain clearance a is reserved between the inner conical surface and the outer conical surface of the conical surface 37.28 under normal conditions, it is a protective valve port, and does not play a role in sealing and isolating gas from passing due to the existence of the gap a during normal work, however, when the sealing structure 37.10 on the valve plate 37.9 is over-long, the valve plate 37.9 will move upward gradually than normal in the valve-closed state along with the change of failure trend, and the conical surface 37.28 will move upward gradually along with the change of the valve plate 37.9, and when the valve plate moves upward to a certain position, in the event of an impending failure of the seal 37.10, the conical surfaces 37.28 on the valve plate 37.9, under the combined action of the valve plate spring 37.8 and the pressure of the gas in the positive pressure inlet chamber 37.7 with the sealing structure 37.29, and the conical valve port 37.30, thereby avoiding the uncontrolled flow of positive pressure gas to the negative pressure gas supply system caused by the failure of the sealing structure 37.10. The diameter of the annular sealing structure 37.29 is the sealing diameter of the conical valve port 37.30. The diameter of the valve plate 37.9 is much larger than that of the sealing port 37.12, and the effective pressure area of the valve plate 37.9 under the action of positive pressure air inlet chamber gas pressure is many times larger, so that the valve closing force obtained by the valve plate 37.9 is increased, and the valve opening force of the valve opening ejector rod 37.15 driven by the diaphragm 37.19 under the same working condition is insufficient to enable the valve plate 37.9 to overcome the valve closing force and move towards the valve opening direction, so that the valve port cannot be normally opened to cut off gas delivery, and the valve plate has the function of reminding and early warning the sealing failure by taking the abnormal work as an expression form on the basis of safety, thereby achieving the purpose of reminding and maintaining the sealing structure 37.10 and ensuring the safe operation of the system. The size of the clearance a is adjusted in the design to ensure that the conical valve port 37.30 seal is effectively activated before the seal 37.10 fails in its sealing performance, according to the fatigue test for the selected seal 37.10.

Fig. 15a, 15b and 15c are enlarged views of the part of the manual valve chamber 37.4 where the manual valve 37.5 is located, wherein fig. 15a is a schematic diagram of the manual valve in an open state in a normal operation state where the gas in the liquefied gas tank has saturated vapor pressure; FIG. 15b is a schematic diagram of the manual valve being in the automatic closing state when the gas in the liquefied gas tank is in the non-normal working state of unsaturated vapor pressure; fig. 15c is a schematic diagram of the manual valve in a closed state when the manual valve is manually closed. In addition, fig. 15a, 15b and 15c are schematic views at the manual valve 37.5 of the negative pressure outlet valve in fig. 11; as shown in fig. 15a, 15b and 15c, a valve core 37.31 is disposed at the frontmost end of the manual valve 37.5, namely, the end close to the first communication conduit 37.3, and the valve core 37.31 is provided with two sets of sealing structures, wherein the first set of sealing structure is disposed at the frontmost end of the valve core 37.31, namely, the end close to the first communication conduit 37.3, and is a cylindrical plunger sealing structure, and a certain gap is formed between the outer diameter of the cylindrical plunger sealing structure and the inner diameter of the first communication conduit 37.3, so as to realize sliding fit; this relatively narrow fit clearance may serve to close the seal or greatly limit the gas flux. The second sealing structure is coaxially arranged behind the cylindrical plunger sealing structure, the sealing structure is a conical sealing structure, and contact sealing can be formed between the conical sealing structure and a conical sealing opening which is arranged behind the coaxially arranged communicating conduit and corresponds to the conical sealing opening, so that a valve closing effect is achieved. The cylindrical body with the outer diameter consistent with the large-diameter end of the conical sealing structure is coaxially arranged behind the conical sealing structure, and the annular gap b formed between the outer diameter of the cylindrical body and the inner diameter of the manual valve cavity 37.4 is used for achieving the effects of flow equalization and flow limitation, so that the valve core 37.31 can be guaranteed to uniformly and fully obtain the force for maintaining the valve opening, which is formed by the impact of gas flow from the communicating conduit. Note that, the flow rate of the so-called restricted flow is not lower than the designed flow rate.

The valve core 37.31 is also provided with a fourth conduit 37.32, the fourth conduit 37.32 is arranged behind the cylinder behind the cone-shaped sealing structure, the outer diameter of the fourth conduit 37.32 is smaller than the outer diameter of the cylinder, a certain sliding fit clearance is formed between the inner diameter of the fourth conduit 37.32 and the outer diameter of the second ejector rod 37.33, and a certain sliding fit clearance is formed between the outer diameter of the fourth conduit 37.32 and the inner diameter of the base 37.34, so that the valve core 37.31 can be guided in movement when opening or closing the valve, and the cylindrical plunger sealing structure, the cone-shaped sealing structure, the cylinder behind the cone-shaped sealing structure and the fourth conduit 37.32 all belong to a part of the valve core 37.31 body and all move together with the valve core 37.31; a second spring 37.35 is further sleeved on the outer diameter surface of the fourth conduit 37.32, one end of the second spring 37.35 is pressed on the rear end surface of the cylinder behind the conical sealing structure, and the other end is pressed on the end surface of the valve core base 37.34 facing to the valve core 37.31, which has the function of providing a certain valve closing force for the valve core 37.31 when the second push rod 37.33 is in the screwing state of manually opening the valve, namely, the second spring 37.35 has the tendency of making the valve core 37.31 move towards the direction of the first communication conduit 37.3; a second push rod 37.33 fixedly connected with a hand wheel of the manual valve 37.5 is arranged behind the fourth guide pipe 37.32 or/and in the fourth guide pipe 37.32, and is used for rotating out to push the valve core 37.31 to a valve closing position or rotating back to release the valve core 37.31 under the control of the hand wheel of the manual valve 37.5 so as to cooperate with the valve core 37.31 to perform the functions of manually closing and opening the valve and also have the function of guiding the movement of the valve core 37.31; behind the fourth conduit 37.32, or/and outside the fourth conduit 37.32, a seat 37.34 is provided, which functions to provide a motion guide for the valve spool 37.31 and also functions as a weighted support for one end of the second spring 37.35.

The specific process of the mutual matching action of the devices is as follows: firstly, as shown in fig. 15a, under a certain environmental temperature condition, when the gas in the liquefied gas tank is in a saturated vapor pressure state and the pressure is sufficiently high, the pressure of the gas in the tank acts on the valve core 37.31 through the communication conduit 37.3, and when the negative pressure outlet combination valve 37 works normally, the valve core 37.31 can be opened, kept opened or closed normally; (II) as shown in FIG. 15b, when the gas in the liquefied gas tank is nearly used up and no gas in a liquid state exists, the gas is in an unsaturated vapor pressure state, and in this state, under the condition that the ambient temperature is kept unchanged, the pressure of the gas in the tank is not kept constant at a certain temperature but gradually decreases at a higher speed along with the continuous extraction and use of the gas equipment to the gas in the tank, when the gas decreases to a certain extent, although the second ejector 37.33 is still in a manually opened state at a turning position, the pressure of the gas in the unsaturated vapor state is not enough to support a certain flow rate to overcome the valve closing force of the second spring 37.35 to the valve plug 37.31, so that the valve plug 37.31 moves towards the valve closing direction, and when the gas moves to a certain extent, particularly when the cylinder sealing structure at the front end starts to perform the sealing function, the flow rate of the gas flowing out through the first communication conduit 37.3 decreases, the air flow is sharply weakened, the pressure difference between the front side space and the back side space of the original valve core 37.31, which is kept due to the existence of the gap b, is also sharply reduced in the manual valve chamber 37.4, in this state, the valve core 37.31 is quickly closed under the action of the second spring 37.35, at this time, the gas equipment 28 or/and the pressurization device 29 which are used as negative pressure power sources cannot be normally opened any more even if the gas pressure in the gas supply pipeline is further reduced, and meanwhile, the gas equipment 28 or/and the pressurization device 29 are also in a low-pressure shutdown alarm prompting state, so that a user is prompted to replace the liquefied gas tank for use, the negative pressure formed in the tank due to the transient extraction of the gas in the liquefied gas tank is prevented, and the risk that the ambient air flows backwards into the liquefied gas tank is avoided; and thirdly, as shown in fig. 15c, in order to manually close the second ejector 37.33 at the unscrewing position, the valve core 37.31 is subjected to a valve closing force exerted by the second ejector 37.33, and a conical sealing structure forms close contact sealing with a conical sealing bead corresponding to the conical sealing bead arranged behind the coaxially arranged communication conduit, so that a valve closing effect is achieved.

Fig. 16a and 16b are a front view and a top view of the valve opening stem 37.15, respectively, as shown in the front view and the top view, a guide wing 37.26 is provided on the circumferential surface of the valve opening stem 37.15, as shown in the top view, the guide wings 37.26 are uniformly and symmetrically arranged along the outer diameter circumference of the valve opening stem 37.15, the number of the guide wings may be 3 or more, but not less than 3, and the guide wings are used for stabilizing the valve opening stem 37.15 by the fit clearance between the guide wings and the valve port 37.11 when the valve opening/closing operation is realized, and the gas can normally pass through the clearance formed between the guide wings.

Fig. 17 is a diagram of the maximum valve opening state of the valve plate 37.9 of the negative pressure outlet combination valve 37, i.e. the valve plate opening height is 1.88mm, the diaphragm and the diaphragm assembly moves downward by 8mm until the valve plate is limited by the maximum moving range of the lever arm and can not move downward any more, and the relative matching position of each part in proportion. It can be seen from the figure that there is no contradiction in the space position design of the negative pressure outlet combination valve 37, and it is reasonable and practical.

Example nine

The ninth embodiment provides a gas supply method, which adopts the gas supply system provided in any one of the first to fourth embodiments to realize gas supply; the gas supply method comprises the following steps: communicating a first valve with an air source, and communicating the first valve with pneumatic equipment through an air supply pipeline; and then the relative pressure of the gas in the gas supply pipeline is modulated through the pneumatic equipment, so that the first valve can be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, and the relative pressure of the gas in the gas supply pipeline can be kept within a first pressure setting range.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, omitted, or some or all of the technical features may be equivalently replaced; and the modifications, omissions or substitutions do not depart from the spirit of the embodiments of the invention.

Claims

1. An air supply system, comprising: the pneumatic device, the gas supply pipeline and the first valve; the first valve is used for being communicated with an air source and is also communicated with the pneumatic equipment through the air supply pipeline; the pneumatic equipment is used for modulating the relative pressure of the gas in the gas supply pipeline, so that the first valve can be opened or closed to control the on-off between the gas source and the gas supply pipeline, and the relative pressure of the gas in the gas supply pipeline can be kept within a first pressure setting range.

2. The air supply system of claim 1, further comprising a first pressure sensor; at least one first pressure sensor is arranged between the first valve and the gas source and is positioned at the upstream of the first valve so as to monitor whether the relative pressure of the gas source is positive pressure.

3. The gas supply system according to claim 2, wherein the first valve is a normally closed solenoid valve or an electrically operated valve; when the relative pressure of the gas in the gas supply pipeline is reduced to be not higher than the lower limit value of the first pressure setting range, the first valve is opened; after the first valve is opened, when the gas delivered by the gas source enters the gas supply pipeline through the first valve and the relative pressure of the gas in the gas supply pipeline rises to be not lower than the upper limit value of the first pressure setting range, the first valve is closed.

4. The gas supply system of claim 3, further comprising a second valve; the second valve is arranged on the air supply pipeline, and the second valve is positioned at the downstream of the first valve; when the relative pressure of the gas in the gas supply pipeline rises to be not lower than the upper limit value of a second pressure setting range, closing the second valve; after the second valve is closed, when the relative pressure of the gas in the gas supply pipeline is reduced to be not higher than the lower limit value of the second pressure setting range, the second valve is opened; the lower limit value of the second pressure setting range is equal to the upper limit value of the first pressure setting range.

5. The air supply system of claim 4, further comprising a first air reservoir; the first air storage tank is arranged on the air supply pipeline, and the first air storage tank is positioned at the downstream of the second valve.

6. The gas supply system of claim 5, further comprising a third valve, wherein the gas supply conduit comprises an outdoor section and an indoor section, and the outdoor section is communicated with the indoor section through the third valve; the third valve is arranged on the gas supply pipeline and is positioned at the downstream of the first gas storage tank; the first valve, the second valve, the first gas storage tank and the third valve are all arranged on the outdoor section in sequence; the pneumatic device is in communication with the indoor section; when the relative pressure of the gas in the indoor section rises to be not lower than the upper limit value of the second pressure setting range, closing the third valve; and after the third valve is closed, opening the third valve when the relative pressure of the gas in the indoor section is reduced to be not higher than the lower limit value of the second pressure setting range.

7. The gas supply system according to claim 6, further comprising a second pressure sensor, wherein at least one of said second pressure sensors is disposed on said first gas tank for monitoring the relative pressure of the gas in said first gas tank.

8. The gas supply system according to claim 6, further comprising a first oxygen content sensor, at least one of said first oxygen content sensors being disposed on said first gas tank for monitoring the oxygen content of the gas in said first gas tank.

9. The air supply system according to claim 8, further comprising a fourth valve and a discharge conduit, wherein the fourth valve is disposed on the discharge conduit, and the first air tank is in communication with the discharge conduit through the fourth valve; the discharge pipeline is also provided with first air extraction equipment, and the tail end of the discharge pipeline is also provided with a dispersion port; the first pumping device is located downstream of the fourth and fifth valves;

when the first oxygen content sensor monitors that the oxygen content of the gas in the first gas storage tank is not lower than the upper limit value of a first oxygen content setting range, the first air pumping equipment is started, the fourth valve is opened in a delayed mode, and the gas in the first gas storage tank is discharged outdoors through the release port; and in the process of discharging the gas in the first gas storage tank to the outside, when the first oxygen content sensor monitors that the oxygen content of the gas in the first gas storage tank is not higher than the lower limit value of the first oxygen content set range, closing the fourth valve, and closing the first air extraction equipment in a delayed manner.

10. The air supply system of claim 9, further comprising a third pressure sensor disposed on the discharge conduit, the third pressure sensor being positioned between the fourth valve and the first pumping device;

and the third pressure sensor is used for opening the fourth valve or/and the fifth valve when monitoring that the pressure value generated at the suction end of the first suction device is not higher than the lower limit value of the first pressure setting range.

11. The gas supply system of claim 9, further comprising a second oxygen sensor, at least one of the second oxygen sensors being disposed on the indoor section for monitoring the oxygen content of the gas in the indoor section.

12. The gas supply system of claim 11, further comprising a fourth pressure sensor, at least one of said fourth pressure sensors being disposed on said indoor section for monitoring the relative pressure of the gas in said indoor section.

13. The gas supply system of claim 12, further comprising a fifth valve disposed on the indoor section; one end of the indoor section is communicated with the third valve, and the other end of the indoor section is communicated with the discharge pipeline through the fifth valve;

when the second oxygen content sensor monitors that the oxygen content of the gas in the indoor section is not lower than the upper limit value of a set range of the second oxygen content, the first air extraction equipment is started, the fifth valve is opened in a delayed mode, and the gas in the indoor section is discharged outdoors through the dispersion port; in the process of discharging the gas in the indoor section to the outdoor, when the second oxygen content sensor monitors that the oxygen content of the gas in the indoor section is not higher than the lower limit value of the set range of the second oxygen content, the fifth valve is closed, and the first air extraction equipment is closed in a delayed manner; the second oxygen content setting range is equal to the first oxygen content setting range;

when the fourth pressure sensor monitors that the relative pressure of the gas in the indoor section is not lower than the upper limit value of a third pressure setting range, the first air suction device is started, the fifth valve is opened in a delayed mode, the gas in the indoor section is discharged to the outside through the release port, the relative pressure of the gas in the indoor section is reduced, meanwhile, the gas supply system is started to alarm, and the first valve, the second valve and the third valve are in an alarm closing state under the alarm state; in the process of discharging the gas in the indoor section to the outdoor, when the fourth pressure sensor monitors that the relative pressure of the gas in the indoor section is not higher than the lower limit value of the third pressure setting range, the fifth valve is closed, the first air extraction equipment is closed in a delayed mode, and meanwhile, the gas supply system continues to keep an alarm prompting state until the gas is recovered after manual troubleshooting; the lower limit value of the third pressure setting range is equal to the lower limit value of the second pressure setting range.

14. The air supply system according to any one of claims 6 to 13, wherein the pneumatic device comprises a sixth valve, a second air extractor device, a second air storage tank and a seventh valve which are communicated in sequence; a fifth pressure sensor is arranged on the second air storage tank; the sixth valve is also in communication with the chamber interior section.

15. The gas supply system according to claim 1, wherein the first valve is a negative pressure gas outlet valve, the negative pressure gas outlet valve comprises a main valve body, a valve plate, a diaphragm and a valve opening mandril, and the main valve body is provided with a normal pressure chamber, a positive pressure gas inlet chamber and a negative pressure gas outlet chamber; the normal pressure chamber is communicated with the main valve body in an external normal pressure environment; the positive pressure air inlet chamber is communicated with a positive pressure air inlet, and the negative pressure air outlet chamber is communicated with a negative pressure air outlet; the valve plate is arranged in the positive pressure air inlet chamber; the valve plate can close a valve port communicated between the positive pressure air inlet chamber and the negative pressure air outlet chamber under the combined action of a valve plate spring and the air pressure in the positive pressure air inlet chamber; the diaphragm is fixedly connected with the valve opening ejector rod, the normal pressure chamber and the negative pressure air outlet chamber are separated by the diaphragm, and when the difference value between the relative pressure of normal pressure air in the external environment of the main valve body and the relative pressure of air in the negative pressure air outlet chamber is larger than a set value, the diaphragm can drive the valve opening ejector rod to move so as to overcome the elastic force of the valve plate spring on the valve plate and the pressure of air pressure in the positive pressure air inlet chamber on the valve plate, and the valve port is opened.

16. The gas supply system according to claim 15, wherein two stages of sealing ring areas with different diameters are coaxially arranged on the valve plate, wherein the sealing ring area with the small diameter of the valve plate is a first stage sealing ring area, and the sealing ring area with the large diameter of the valve plate is a second stage sealing ring area; the valve port is coaxially provided with two stages of sealing ring areas corresponding to the valve plate, wherein the sealing ring area with the small diameter of the valve port is a first stage sealing ring area, and the sealing ring area with the large diameter of the valve port is a second stage sealing ring area;

under the normal working state, the primary sealing ring area of the valve plate is in contact with the primary sealing ring area of the valve port to close the valve port, and the secondary sealing ring area of the valve plate is not in contact with the secondary sealing ring area of the valve port;

when the first-stage sealing ring area of the valve plate fails, the second-stage sealing ring area of the valve plate is in contact with the second-stage sealing ring area of the valve port to close the valve port.

17. The air supply system according to claim 15 or 16, characterized in that a manual valve chamber is provided on the positive pressure intake port between the positive pressure intake chamber and the positive pressure intake chamber, the manual valve chamber being communicated with the positive pressure intake port through a first communication conduit, the manual valve chamber being communicated with the positive pressure intake chamber through a second communication conduit;

and a manual valve is arranged in the manual valve chamber and used for preventing negative pressure from being formed on one side where the positive pressure air inlet is located, and the manual valve is also used for manually controlling the on-off of the positive pressure air inlet and the positive pressure air inlet chamber.

18. The air supply system of claim 17, wherein the manual valve comprises a valve core, a fourth conduit, a second push rod, a second spring and a hand wheel;

the valve core comprises a cylindrical plunger sealing structure, a conical sealing structure and a cylinder which are coaxially arranged with the cylindrical plunger sealing structure, wherein the cylindrical plunger sealing structure, the conical sealing structure and the cylinder are sequentially connected;

one end of the fourth conduit is closed, the closed end of the fourth conduit is abutted against the cylinder of the valve core, and the diameter of the fourth conduit is smaller than that of the cylinder;

one end of the second ejector rod is slidably arranged in the fourth guide pipe, the other end of the second ejector rod is fixedly connected with the hand wheel, and the second ejector rod can be arranged on the main valve body in a threaded connection mode;

the second spring is sleeved on the outer side of the fourth guide pipe, one end of the second spring is abutted to one end of the cylinder, and the other end of the second spring is abutted to the inner wall of the manual valve chamber.

19. The air supply system according to claim 15, wherein the number of the pneumatic devices is one or more, and the number of the first valves is one or more.

20. A method of supplying gas, comprising:

communicating a first valve with an air source, and communicating the first valve with pneumatic equipment through an air supply pipeline; and then, modulating the relative pressure of the gas in the gas supply pipeline through the pneumatic equipment so as to enable the first valve to be opened or closed to control the connection and disconnection between the gas source and the gas supply pipeline, so that the relative pressure of the gas in the gas supply pipeline can be kept within a first pressure setting range.